The study aims to investigate the impact of planting density on the yield and quality of the newly approved high-quality weak gluten wheat variety 'Yunmai 114' in Yunnan, providing a theoretical basis for determining a reasonable planting density for the large-scale promotion of weak gluten wheat varieties in Yunnan. Using 'Yunmai 114' as the experimental material, seven treatments including 900000 plants/hm² (A), 1.35 million plants/hm² (B), 1.8 million plants/hm² (C), 2.25 million plants/hm² (D), 2.7 million plants/hm² (E), 3.15 million plants/hm² (F), and 3.6 million plants/hm² (G) were set up for basic seedlings, with three replicates and incomplete random block arrangement. The yield and yield related traits, grain type traits, quality traits and stem tiller dynamics of the variety were investigated under different planting densities, and variance analysis and correlation analysis were conducted on these traits. The highest number of tillers, effective panicles, and the number of tillers in the third, fourth, fifth, sixth, and seventh leaf stages of 'Yunmai 114' showed extremely distinct differences at 7 planting densities. There were also significant differences in spike rate, grain number, plant height, water absorption rate, protein content, stable time, formation time, and hardness value at each planting density. However, there were no significant differences in theoretical yield, actual yield, thousand grain weight, grain area, grain circumference, grain length to width ratio, and grain length and width among different planting densities. The changes in both theoretical and actual yields showed a trend of first increasing, then decreasing, then increasing, and finally decreasing with the increase of planting density. There was a highly significant positive correlation (r=0.778**, 0.908**, 0.767**, 0.924**, 0.850**, and 0.752**) between the effective panicle, the number of tillers in the third, fourth, fifth, sixth, and seventh leaf stages of the variety and its basic seedlings. The plant height and theoretical yield were significantly positively correlated with their basic seedlings (r=0.536* and 0.520*). There was a significant negative correlation between the number of grains per panicle, protein content and stability time with their basic seedlings (r=-0.450*, -0.449*, and -0.467*), while there was a certain correlation but not significant between actual yield and 16 other traits with the basic seedlings. Planting density could significantly affect the number of tillers in the third, fourth, fifth, sixth, and seventh leaf stages, highest tiller number, effective panicle, spike rate, grain number, plant height, water absorption rate, protein content, stability time, formation time, and hardness value of 'Yunmai 114', but it did not significantly affect the theoretical yield, actual yield, thousand grain weight, grain area, grain circumference, and grain length to width ratio, grain length and grain width. Moreover, a low planting density was not conducive to the performance of the yield and quality characteristics of the variety. When the basic seedlings were 1.35 million -3.6 million plants/hm², the yield of the variety remained stable at 14389.50-16078.50 kg/hm², maintaining good yield and stability, as well as maintaining the quality characteristics of weak gluten wheat. These planting densities are suitable for promotion in areas with better water and fertilizer conditions in Yunnan.

The aim was to understand the incidence and resistance performance of black point disease in major cultivated wheat varieties in the Huang-Huai wheat region. A total of 33 wheat varieties from the region were collected, and the rates of black point kernel in grains and diseased index were statistically analyzed for each variety. Disease index was also analyzed, and the resistance to black point disease was categorized. Significant differences in the rate of black point kernel were observed among the tested wheat varieties (lines), with the rate of black point kernel ranging from 6.17% to 63.17%. Varieties such as ‘Bainong 607’, ‘Bainong 207’, ‘Shannong 17’, ‘Shannong 116’, ‘Weilong 169’, and ‘Xinmai 45’ had low rates of black point kernel in grains and a light disease index, all were classified as having a low susceptibility to wheat black point disease; whereas ‘Zhoumai 36’, ‘Zhoumai 28’, ‘Gaomai 6’, ‘Tunmai 127’, ‘Anke 1602’, and ‘Aikang 58’ had high rates of black point kernel in grains and a heavy disease index, all were classified as having a high susceptibility to wheat black point disease. There were significant differences in the rate of black point kernel among different wheat varieties in the Huang-Huai wheat region. The research results provide important information for variety selection and disease management in the region, which will help guide agricultural production practices, reduce the occurrence of black point disease, and improve wheat yield and quality.

To investigate the occurrence of weeds in wheat fields in Changzhou area, Jiangsu Province and their impact on wheat production, a large-scale survey of weed occurrence in wheat fields, as well as surveys of weed occurrence in wheat fields under different tillage methods (deep tillage, shallow rotation) were organized, different chemical treatments were set up (treatment A, 33% fluoxystrobin·furoxime·pyrifluoroacetamide; treatment B, 35% fluoxystrobin·pyrifluoroacetamide; treatment C, 41% fluoxystrobin; treatment D, 60% propiconazole·iprone; treatment E, 20% fluoxystrobin; with water as a control) to explore the effects of each treatment on wheat production, including weed occurrence, yield, etc. The results showed that the occurrence of weeds in wheat fields in the study area showed a gradually increasing trend, the changes of monocotyledonous weeds more obvious. The main dominant species were Poaceae weeds such as Alopecurus japonicus, Alopecurus aequalis, and Beckmannia syzigachne. Compared with shallow rotation, deep tillage tends to exacerbate weed occurrence. All treatments were safe for wheat growth, among them, treatment A had the least weeds in the field and the highest wheat yield; in terms of the impact of weeds on yield, it mainly affected the number of spikes per unit area of wheat, and then affected yield, with the number of monocotyledonous weeds having the greatest impact on spike number 50 days after application. The research provides references for efficient weed control in wheat fields.

【Objective】 The study aims to measure the iron (Fe) concentration in the grain, flour, and bran of newly developed high-yielding wheat varieties (lines) in major wheat production regions of China. It investigates the impact of yield, yield components, and soil factors on Fe absorption and distribution within the wheat, and determine the effects of these variables on Fe concentrations in its different parts. The objective is to provide a basis for grain Fe nutritional fortification in wheat. 【Method】A study was conducted on 104 newly developed wheat varieties (lines) through multi-point trials across 17 provinces in major wheat production regions of China. The research analyzed Fe concentration in wheat grain, flour and bran, along with yield, yield components, Fe absorption and distribution, soil physicochemical properties, and fertilizer application rates during the 2021-2022 and 2022-2023 growing seasons, to study the Fe concentration in different parts of the grain of newly developed wheat varieties (lines) in China, as well as the absorption and distribution of Fe and environmental influencing factors. 【Result】Significant variations for Fe concentrations were observed in the wheat grain, flour and bran among new varieties (lines) in the major wheat production regions of China,with the range of 20.2-57.1, 2.1-37.5, and 31.2-144.5 mg·kg^-1, and the average of 34.6, 10.8, and 72.8 mg·kg^-1, respectively. Wheat varieties (lines) in the southern wheat regions exhibited higher Fe concentrations in grains and its different parts compared to that in the northern regions, and the Fe concentration in flour and bran showed a positive correlation with its in grain. For every 1.0 mg·kg^-1 increase in grain Fe, flour saw a 0.2 to 0.3 mg·kg^-1 rise, and bran experienced a 1.9 to 2.3 mg·kg^-1 increase. The Fe concentration in grains was negatively correlated with yield, biomass, and spike number. With each 1.0 t·hm^-2 increase in yield, there was a decrease of 1.2 mg·kg^-1 in grain Fe concentration. For every 100×10⁴/hm² increase in spike number, the grain Fe concentration decreased by 0.3 mg·kg^-1. The flour Fe concentration showed negative relationship with Fe absorption in grain, straw, glume and bran. The grain Fe concentration was negatively correlated with calcium, and positively with manganese, copper, and zinc. The grain Fe concentrations varied over locations, and different locations contributing 39% to 70% to the variation in grain Fe concentration. Soil pH, available phosphorus, Fe and manganese as major environmental factors affecting Fe nutrition in wheat grains. Grain Fe concentrations were negatively correlated with soil available phosphorus. Meanwhile, flour Fe concentrations were negatively correlated with soil pH, and positively correlated with soil available iron and manganese. 【Conclusion】High-Fe varieties (lines) were found among the newly developed high-yielding wheat varieties (lines) in China. Maintaining stable spike number, regulating soil pH, increasing grain Fe harvest index, soil available phosphorus, iron, manganese and appropriately applying N, P to enhance soil fertility were conducive to achieving a synergistic enhancement of both yield and Fe concentrations in wheat grain and flour.

【Objective】Aiming at the problems of large amount of nitrogen fertilizer input, low utilization rate and single fertilizer source in traditional spring wheat planting in the oasis irrigation area of Northwest China, the effects of multiple cropping green manure after spring wheat on photosynthetic source, growth characteristics and yield of spring wheat under the condition of reduced nitrogen application were studied, with a view to provide the technical support for the construction of a nitrogen-saving and high-yield green planting model of spring wheat in the experimental area. 【Method】The split plot experiment was carried out in the oasis irrigation area of Hexi Corridor from 2021 to 2023. The main area was set up with two planting modes: post-wheat fallow (W) and post-wheat multiple cropping of hairy leaf (W-G), and the split plot was the traditional full nitrogen application of 100% (N1, 180 kg·hm^-2), reduced nitrogen application of 15% (N2, 153 kg·hm^-2) and reduced nitrogen application of 30% (N3, 126 kg·hm^-2). The photosynthetic source, stay-green of leaves, growth characteristics and yield performance related indicators of spring wheat under different treatments were measured and calculated. The Logistic equation of dry matter accumulation, the correlation between different indicators and the compensation index were constructed. The objective was to explore the compensation effect of multiple cropping green manure on the growth and yield of nitrogen-reduced spring wheat. 【Result】Post-wheat multiple cropping of green manure could compensate for the loss of photosynthetic source, growth characteristics and yield caused by nitrogen reduction to a certain extent. Among them, the compensation effect was the best under the condition of multiple cropping green manure after spring wheat combined with 15% nitrogen reduction (W-GN2), which showed super compensation and equal compensation effect. Multiple cropping of green manure significantly increased leaf area index, leaf area duration and stay-green of leaves in spring wheat at the late reproductive stage. Compared with the traditional post-wheat fallow total nitrogen fertilization (WN1), W-GN2 increased the average leaf area index, leaf area duration and stay-green of leaves by 17.7%, 17.5% and 7.6% on the 75-90 days after seedling, respectively. W-GN2 optimized the growth characteristics of spring wheat. Compared with WN1, the average dry matter accumulation, the maximum growth rate of dry matter and crop growth rate under W-GN2 increased by 6.2%, 6.9% and 5.1%, respectively, and the net assimilation rate decreased by 6.2%. Due to the compensation of multiple cropping green manure for photosynthetic source and growth characteristics, the photosynthesis, population growth and material accumulation rate of spring wheat remained high in the late growth stage, which was conducive to the improvement of grain yield. The grain yield under W-GN2 was 14.7% higher than that under WN1, which was mainly attributed to the compensation of the spike number, 1000-grain weight and harvest index by multiple cropping green manure, and W-GN2 was 6.5%, 6.9% and 13.2% higher than that under WN1, respectively. According to the correlation analysis, it was found that W-GN2 treatment had better performance in photosynthetic source, growth characteristics and grain yield formation, and mainly promoted the formation of yield by compensating the photosynthetic source of spring wheat. 【Conclusion】Multiple cropping of hairy vetch after spring wheat with 15% reduction of nitrogen application could be used as a perfect production technology to regulate the photosynthetic source and growth characteristics of spring wheat in the northwest oasis irrigation area to achieve nitrogen saving and yield increase.

To screen for safe and efficient herbicides for the control of gramineous weeds in winter wheat fields, a comparative efficacy trial was conducted using 5 commonly used herbicides, including 3% mesosulfuron-methyl SC, and others. The trial analyzed the impact of these herbicides on wheat safety, weed control efficacy (plant control efficacy and fresh weight control efficacy, immediate and delayed effectiveness of the herbicides, and the types of weeds controlled), and the rate of loss recovery. The results showed that the application rates of the 5 tested herbicides were safe for the growth of wheat in the 4-5 leaf overwintering stage. The weed control and pest suppression effects of 3% mesosulfuron-methyl SC, 5% pinoxaden EC, and 75% flucarbazone-sodium WG were the best, with plant control efficacies of 94.01%, 83.03%, and 74.65%, respectively, 110 days after application, the fresh weight control efficacies were 94.97%, 88.56%, and 82.97%, respectively. Among them, 5% pinoxaden EC and 7.5% pyroxsulam WG had better immediate control effects, while 3% mesosulfuron-methyl SC and 5% pinoxaden EC had longer-lasting effects. 5% pinoxaden EC was the most effective in controlling Alopecurus aequalis and Alopecurus japonicus, while 3% mesosulfuron-methyl SC was the most effective in controlling Beckmannia syzigachne. Compared with the control plots, the recovery rates of wheat loss under 3% mesosulfuron-methyl SC, 5% pinoxaden EC, and 75% flucarbazone-sodium WG were 29.28%, 25.18%, and 22.40%, respectively. In practice, herbicides with different action mechanisms should be used alternately to control weeds in wheat fields.

Starting from the wheat production practice in Yushan District, Ma’anshan, Anhui Province, the causes, main disease symptom, hazards, and prevention and control measures were summarized and analyzed of scab in this crop. Wheat scab is one of the important diseases affecting wheat production caused by Fusarium spp., and is a typical climatic disease. The research area belongs to the transitional zone of the northern subtropical monsoon, and the climatic conditions are favorable for the infection of Fusarium; at the same time, the high-amount of fungal sources in the field, weak resistance of planting varieties, improper cultivation methods and management can exacerbate the occurrence and spread of the disease to a certain extent. This disease can cause a large-scale reduction in wheat yield, and the toxins in the diseased ears can also cause harm to humans and livestock. Based on this, the strategies were proposed to establish a monitoring and early warning system to timely grasp the dynamic occurrence of diseases; improve cultivation and management techniques such as timely and appropriate sowing, scientific fertilization, and field management; standardize straw returning, application of base fertilizer, and introduction of biological control bacteria to reduce the base of pathogenic bacteria in the field; breeding and planting disease resistant varieties using molecular markers and other techniques; adopt scientific chemical prevention and control measures such as seed mixing with pesticides, appropriate timing of medication, alternating and rotating medication, and selecting suitable machinery; timely harvesting, drying, and storage, as well as strengthening collection and storage management for preventing and controlling wheat scab, provides references for comprehensive prevention and control of scab in wheat production in related area.

In order to optimize wheat sowing date in the Jianghan Plain, enhance the adaptability to climate change, and promote wheat yield and quality, the temporal and spatial characteristics of meteorological suitability in winter wheat were compared based on the meteorological suitability evaluation model. Results showed that, climate change could increase the temperature suitability and precipitation suitability, but reduced that of sunlight. Delaying the sowing date could appropriately improve the meteorological suitability. Among them, November 11^th was the best sowing date, next was November 21^st and November 1^st, by enhancing the temperature and precipitation suitability from the jointing to maturity stage. Compared with the traditional sowing date (October 21^st), delaying sowing for about 20 days (November 11^th) is beneficial for improving the meteorological suitability in the Jianghan Plain.

Nitrogen (N) uptake is regulated by water availability, and a water deficit can limit crop N responses by reducing N uptake and utilization.  The complex and multifaceted interplay between water availability and the crop N response makes it difficult to predict and quantify the effect of water deficit on crop N status.  The nitrogen nutrition index (NNI) has been widely used to accurately diagnose crop N status and to evaluate the effectiveness of N application.  The decline of NNI under water-limiting conditions has been documented, although the underlying mechanism governing this decline is not fully understood.  This study aimed to elucidate the reason for the decline of NNI under water-limiting conditions and to provide insights into the accurate utilization of NNI for assessing crop N status under different water–N interaction treatments.  Rainout shelter experiments were conducted over three growing seasons from 2018 to 2021 under different N (75 and 225 kg N ha^–1, low N and high N) and water (120 to 510 mm, W0 to W3) co-limitation treatments.  Plant N accumulation, shoot biomass (SB), plant N concentration (%N), soil nitrate-N content, actual evapotranspiration (ET_a), and yield were recorded at the stem elongation, booting, anthesis and grain filling stages.  Compared to W0, W1 to W3 treatments exhibited NNI values that were greater by 10.2 to 20.5%, 12.6 to 24.8%, 14 to 24.8%, and 16.8 to 24.8% at stem elongation, booting, anthesis, and grain filling, respectively, across the 2018–2021 seasons.  This decline in NNI under water-limiting conditions stemmed from two main factors.  First, reduced ET_a and SB led to a greater critical N concentration (%N_c) under water-limiting conditions, which contributed to the decline in NNI primarily under high N conditions.  Second, changes in plant %N played a more significant role under low N conditions.  Plant N accumulation exhibited a positive allometric relationship with SB and a negative relationship with soil nitrate-N content under water-limiting conditions, indicating co-regulation by SB and the soil nitrate-N content.  However, this regulation was influenced by water availability.  Plant N accumulation sourced from the soil nitrate-N content reflects soil N availability.  Greater soil water availability facilitated greater absorption of soil nitrate-N into the plants, leading to a positive correlation between plant N accumulation and ET_a across the different water–N interaction treatments.  Therefore, considering the impact of soil water availability is crucial when assessing soil N availability under water-limiting conditions.  The findings of this study provide valuable insights into the factors contributing to the decline in NNI among different water–N interaction treatments and can contribute to the more accurate utilization of NNI for assessing winter wheat N status.

The trade-off between yield and environmental effects caused by nitrogen fertilizer application is an important issue in wheat production.  A reduction in fertile florets is one of the main reasons for the lower yields under low nitrogen application rates.  Brassinosteroids (BRs) have been found to play a role in nitrogen-induced rice spikelet degeneration.  However, whether BRs play a role in wheat floret development and the mechanisms involved are not clear.  Therefore, a nitrogen gradient experiment and exogenous spraying experiment were conducted to investigate the role and mechanism of BRs in wheat floret development under low nitrogen stress.  The results showed that as the nitrogen application decreased, the endogenous BRs content of the spikes decreased, photosynthesis weakened, and total carbon, soluble sugar and starch in the spikes decreased, leading to a reduction in the number of fertile florets.  Under low nitrogen stress, exogenous spraying of 24-epibrassinolide promoted photosynthesis, and stimulated stem fructan hydrolysis and the utilization and storage of sucrose in spikes, which directed more carbohydrates to the spikes and increased the number of fertile florets.  In conclusion, BRs mediate the effects of nitrogen fertilizer on wheat floret development, and under low nitrogen stress, foliar spraying of 24-epibrassinolide promotes the flow of carbohydrates from the stem to the spikes, alleviating wheat floret degeneration.

【Objective】Based on the long-term experiment in the North China Plain (NCP), the differences in soil nutrient and aggregate nutrient distribution between diversified crops and wheat-maize rotation systems were investigated. Additionally, it provided a comprehensive evaluation of soil quality indices (SQI), offering a scientific basis for enhancing soil quality and productivity in the NCP. 【Method】Four diversified crop rotation systems were evaluated, including spring sweet potato-winter wheat-summer maize (Psw-WM), spring peanut-winter wheat-summer maize (Pns-WM), spring sorghum-winter wheat-summer maize (Ps-WM), with winter wheat-summer maize (WM-WM) serving as the control. The soil samples from the 0-40 cm depth were collected during the second rotation in 2022, at the flowering and harvesting stages of winter wheat. The soil enzymes activities, aggregate stability, organic matter, and concentrations of nitrogen, phosphorus, and potassium in soil and aggregates of different sizes (>2.00 mm, 0.50-2.00 mm, 0.25-0.50 mm, and <0.25 mm) were assessed. The SQI for each crop rotation system was then comprehensively evaluated. 【Result】Compared with WM-WM, the three other crop rotations increased soil inorganic nitrogen content. Psw-WM significantly enhanced organic matter in the 0-20 cm layer, total nitrogen in soil aggregates (>2.00 mm, 0-10 cm), and organic matter in soil aggregates (>2.00 mm and 0.50-2.00 mm, 0-10 cm), which also increased cellulase, catalase, and alkaline protease activities. Pns-WM improved organic matter in the 20-40 cm layer and available potassium in soil aggregates (0.25-0.50 mm and >2.00 mm, 10-20 cm), as well as organic matter in soil aggregates (0-10 cm, >2.00 mm and 10-20 cm, >0.50 mm), which also increased sucrase, urease, and alkaline protease activities. Psw-WM improved the stability of 0-10 cm soil aggregates, while Pns-WM improved the stability of 0-30 cm soil aggregates. Both Pns-WM and Psw-WM significantly improved the SQI, with Pns-WM showing a higher improvement than Psw-WM. The path analysis revealed that the average weight diameter (MWD) of aggregates was a direct and significant affecting SQI. It also had a significant indirect positive effect on SQI by influencing inorganic nitrogen. Additionally, the increased organic matter led to a higher proportion of large aggregates, which significantly affected SQI indirectly. 【Conclusion】Legume (peanut) and root crop (sweet potato) rotations with wheat-maize rotations could significantly improve soil quality and enhance the soil nutrient supply capacity in the NCP.

【Objective】 This study was to clarify differences of zinc (Zn) concentration in wheat grain and flour and the corresponding affecting factors over major wheat production regions, with the purpose to provide the theoretical basis for improving the Zn nutritional quality of wheat grain in China. 【Method】During 2020-2021 and 2021-2022 wheat growing seasons, 421 wheat and soil samples were collected from major wheat production regions in 17 provinces and autonomous regions of China, to explore the relationship of Zn concentration in wheat grain, flour and bran with wheat yield, yield components and soil properties.【Result】The average Zn concentration of the wheat grain, flour and bran was 28.1, 10.8 and 60.6 mg·kg^-1, respectively, with 94.8% of grain and 89.5% of flour samples could not meet with the recommended Zn concentration of 40 mg·kg^-1 for grain and 15 mg·kg^-1 for flour by nutritionists. The highest grain Zn concentration was observed in rice-wheat region (RW), followed by that in wheat-maize regions (MW) and dryland wheat region (DW), and the lowest was in spring-wheat region (SW). In rice-wheat region, the lower pH promoted the activation of soil Zn, and its availability was significantly higher than that in other regions, the lowered phosphorus fertilizer application rate was also conducive to Zn absorption and its translocation from root to the aboveground, and the average Zn concentration in wheat grains and flour was therefore as high as 31.5 and 12.2 mg·kg^-1, respectively. In wheat-maize region, the soil fertility was higher, so that the yield was significantly greater than that in other wheat regions, resulting in relatively lower Zn concentrations in wheat grains and flour, which were 27.1 and 10.3 mg·kg^-1, respectively. In dryland wheat region, the higher soil pH limited soil Zn availability and wheat Zn absorption, leading to the grain and flour Zn concentration being relatively lower as 26.5 and 10.1 mg·kg^-1, respectively. In spring-wheat region, since the soil available Zn concentration was significantly lower than that in other wheat regions, which was not conducive to Zn absorption by wheat and its accumulation in grain, and therefore the Zn concentrations in grain and flour were the lowest as 24.6 and 9.4 mg·kg^-1, respectively, while Zn concentration decreased significantly with the increase of 1000-grain weight.【Conclusion】 Therefore, in order to improve the Zn concentration of wheat grains and flour, it was not only necessary to improve the soil pH, available Zn level and reasonable nitrogen and phosphorus fertilizer application, but also jointly to optimize the yield components to improve the wheat yield and grain and flour Zn concentration.

The study aimed to provide theoretical support for identifying the growth characteristics of new wheat strains in Huaibei District, Jiangsu Province, and for new varieties breeding direction and green high-efficiency and high-yield cultivation technology measures in Xuzhou and the same ecological area. Multiple agronomic character data and meteorological data such as temperature, precipitation and light during wheat growth period of 335 new wheat lines in Huaibei wheat regional experiment in Jiangsu Province from 2004 to 2022 were used to analyze the evolution law and their correlation in the past 20 years. The results showed that during the wheat growing period, the total precipitation increased by 2.1451 mm per year, and the total sunshine duration decreased by 5.5074 h per year. In January, February and March, the overall temperature rise was obvious, the overwintering period of wheat was gradually shortened, and the regreen jointing period was advanced. The proportion of increased wheat varieties in the test was fluctuating, but the overall trend was rising. The basic seedlings, maximum tiller, plant height, volume weight, number of ears and grain yield showed an increasing trend, the growth period was slightly shortened; the 1000-grain weight and grans per spike were basically flat, but slightly decreased. The coefficient of variation was the smallest in the growth period (2.71%). The highest number of tillers per hectare was 19.86%. The coefficient of variation of growth period, bulk weight and plant height was less than 10%, and the coefficient of variation of other traits was more than 10%. The results of comparison between the top 10 and the bottom 10 showed that wheat lines with more than 6.2 million panicle number, more than 35 grains per spike, more than 43g 1000-grain weight and more stable agronomic traits were more likely to obtain high yield. The correlation analysis results showed that the three factors of yield were positively correlated with yield, while the effective panicle number was negatively correlated with 1000-grain weight and the number of grains per panicle. Cultivating new varieties with three factors of yield synergistic improvement and matching cultivation measures to cope with climate change is an important way to achieve high and stable yield of wheat in Xuzhou and the same ecological area.

Climatic factors are the main factors affecting crop growth and development, and have a significant impact on crop growth, yield, and quality. In order to explore the characteristics of climate factor changes in northern Henan and their impact on winter wheat production, this study used agrometeorological observation data of winter wheat from 1984 to 2022 in Qinyang County, Henan Province, combined with meteorological observation data from the same period, and used methods such as linear tendency estimation, Mann Kendall test, HP filtering, and correlation analysis to study the quantitative impact of climate factor changes and climate yield during the growth period of winter wheat. The results showed that from 1984 to 2022, the temperature during the growth period of winter wheat showed a significant fluctuation and upward trend, with a climate tendency rate of 0.35℃/10a (P<0.05). There were obvious seasonal changes in temperature during the growth period, and a sudden change in temperature occurred in 1994. In the past 39 years, the accumulated temperature at ≥0℃ had increased, with a climate tendency rate of 53.5℃/10a (P>0.05), and the mutation points were in 2010 and 2021. The precipitation and sunshine hours during the growth period showed a fluctuating decreasing trend, with the linear tendency rates of 13.4 mm/10a (P>0.05) and -43.0 h/10a, respectively. Affected by climate change, the duration of winter wheat growth season was significantly shortened, and the yield was greatly affected by climate factors. Within a certain temperature range, the climate yield of winter wheat increased with the increase of temperature. For every 1℃ increase in temperature, the climate yield increased by 14.53 g/m². The suitable threshold for accumulated temperature of ≥0℃ during the growth period was 2281℃. There are differences in the impact of climate factors on the climate yield of winter wheat in different growth periods. The sunshine hours from tillering to over wintering, booting to heading, booting to heading temperature, heading to flowering, and precipitation throughout the entire growth period are key factors affecting winter wheat yield. This study can provide important references for regional winter wheat response to climate change and agricultural scientific decision-making.

To investigate the effect of fertilization amount on the growth, development, and yield of winter wheat, 2 winter wheat varieties, Zangdong 20 and Shandong 7 were used as materials, and low fertilizer, medium fertilizer, and high fertilizer treatments were set to explore their effects on this plant phenological period, agronomic traits, and yield, to explore the optimal fertilizer application rate. The results showed that under different fertilization treatments, the full growth period of 2 winter wheat varieties was 264-281 days, with the medium fertilizer treatment having the longest full growth period. Under different fertilization treatments, both winter wheat varieties showed better agronomic traits in terms of plant height, stem diameter, and stem node length under the ear when treated with medium fertilizer. In terms of yield and yield composition, the basic number of seedlings, total number of tillers, fertile spikelets, number of grains per spike, single spike grain weight, single plant grain weight, and yield were higher in the medium fertilizer treatment, while the sterile spikelets were lower, and the highest yield of Zangdong 20 was higher than that of Shandong 7. The medium fertilizer treatment is beneficial for wheat growth and has a higher efficiency in absorbing and utilizing fertilizers. Overall, medium fertilizer treatment can effectively extend the wheat jointing stage to heading stage, allowing it to absorb and accumulate more nutrients, and the agronomic traits showed better performance, with a significant increase in yield. The high-efficiency planting model of winter wheat Zangdong 20 + medium fertilizer level can be adopted.

Anke 1618 is a new semi-winter wheat variety with Shiyou 17 as the mother and Zhoumai 18 as the father. It had the characteristics of high-yield, stable-yield, wide adaptability and strong disease resistance. The breeding process, agronomic traits such as whole growth period, plant height, panicle number and yield of this variety were summarized and analyzed. The average yield of this variety was 8 468.4 kg/hm² in the regional experiment of Wanhuai wheat complex in 2018-2019 and 2019-2020. In the 2020-2021 production test, the average yield was 8 501.3 kg/hm², and the yield increase point rate of multiple tests was more than 60%. Its comprehensive agronomic traits were good, disease resistance was better, quality was superior; high-yield cultivation emphasized uniform seed mixing and selecting suitable sowing dates; reasonable fertilization; field management focused on seedling inspection and supplementation, winter irrigation, comprehensive prevention and control of pests, diseases, and weeds, as well as field impurity removal. The research provides references for the cultivation and popularization of this variety in the north of Huaihe River and Huaihe River region.

In order to explore the potential advantages of ‘Chuanmai 614’, and better serve production and application, this study analyzed its yield performance. Using 3-year regional trial data, the yield, stability and adaptability of ‘Chuanmai 614’ were studied using the analysis method of multi-year and multi-point comparison test and the GGE biplot model. The results showed that the average yield of ‘Chuanmai 614’ was 6031.50 kg/hm², ranking second, with good stability and adaptability to multiple environments. In the production experiment, the average yield of ‘Chuanmai 614’ was 7031.55 kg/hm², which ranked the first, and there was an increase of 8.79% compared to the control. Among the GGE biplot model analysis, the ‘variety with highest yield in different places’ functional diagram indicated that ‘Chuanmai 614’ had high production and good adaptability in Dazhou, Neijiang, Nanbu, Shuangliu, and Zhongjiang; the functional diagram of ‘high yield and stable yield’ showed that among all the varieties, ‘Chuanmai 614’ had the highest yield and good stability. The GGE biplot chart with concentric circles indicated that ‘Chuanmai 614’ had good yield and stability. Overall, ‘Chuanmai 614’ is a new nutrient efficient variety with good yield and stability.

To clarify the mechanism of the effect of short-term fertilization on the composition and diversity of soil bacterial communities in wheat fields, a field experiment was conducted with four treatments: no fertilization (T₁), conventional fertilization (T₂), recommended fertilization (T₃) and organic substitution of 50% (T₄), by using high-throughput sequencing to study the effects on soil bacterial community composition and diversity. The results showed that compared with T₁ treatment, fertilization treatments decreased soil pH value, but T₄ treatment delayed the downward trend of pH; T₂, T₃ and T₄ increased the yield by 147.45%, 144.68% and 98.41%, respectively. The T₄ treatment increased the Shannon index and decreased the soil bacterial Chao index, but the differences were not significant. Fertilization increased the relative abundance of soil Proteobacteria, among which T₂ was the highest, while fertilization decreased the relative abundance of Cyanobacteria, among which T₄ was the highest. T₂ enriched g_Roseateles, g_Rhodanobacter and g_Singulisphaera, T₄ enriched g_Pseudoxanthomonas and o_Streptosporangiales. Cluster analyses showed that alkali-hydrolyzable nitrogen, available phosphorus, available potassium and organic carbon had similar effects on bacterial flora, but pH was different. Compared with T₂, T₄ slowed down the evolution of photoautotrophic flora to chemo-energy heterotrophic flora and decreased the abundance of nitrate respiration-related flora. Therefore, short-term organic substitution (50%) has the risk of reducing yield, but it was beneficial to maintain the stability of bacterial community in wheat field. N 150 kg/hm² could be used as the recommended amount of fertilization.

China is a major agricultural country. With the rapid development of agricultural science and technology, agriculture has entered a new stage of development with high yield, high quality, and high efficiency. Achieving automation and intelligent observation of crop growth period recognition is a crucial part of agricultural modernization. This paper introduced the current research status of crop growth period recognition and presented two methods for automatic observation and identification of winter wheat growth period, one based on the Normalized Difference Vegetation Index (NDVI) and the other based on deep learning. Using winter wheat in Henan as an example, the results of automatic observation and identification from both methods were compared with manual observations. The results validated the feasibility and effectiveness of both identification methods, showing high accuracy and efficiency, thereby improving measurement efficiency and reliability. In terms of identification accuracy, the two methods had their own strengths at different growth periods and could complement each other. The deep learning-based identification method demonstrated better generalizability compared to the NDVI-based method. However, both methods required optimization and upgrading in the future to further enhance identification accuracy.

To explore the influence of biochar on soil structure and wheat yield under different irrigation conditions, the experiment was conducted in combination of field experiment and indoor experiment. Two levels of biochar application, 0 t/hm² (B₀) and 20 t/hm² (B₁), and two levels of irrigation amount, 4500 m³/hm² (W₀) and 4050 m³/hm² (W₁) were set to investigate the distribution of soil aggregates, stability changes and wheat yield. The results showed that the application of biochar and the reduction of irrigation water would affect soil aggregate distribution and soil aggregate stability. In the 0-20 cm soil layer, biochar application increased the soil aggregate content of > 2 mm GMD and MMD, but reduced irrigation would decrease the soil aggregate content of > 2 mm and reduce the stability of soil mechanical aggregate. In the soil layer of 20-40 cm, the trend between each treatment was basically consistent with that of the 0-20 cm soil layer. However, the application of biochar in conjunction with reduced irrigation can maintain the stability of soil mechanical aggregates and increase winter wheat yields to a certain extent. The highest winter wheat yield was recorded in B₁W₁ treatment, which was 9.73 % higher than that of B0W0 treatment. In conclusion, under the conditions of this experiment, the appropriate reduction of irrigation volume (4050 m³/hm²) and the application of biochar (20 t/hm²) could significantly improve the distribution and stability of soil aggregates in wheat fields in the irrigated area, which was conducive to the improvement of soil structure and the increase of wheat yield.

In order to screen the high-quality black wheat germplasm resources for color wheat breeding and guide the black wheat industrialization, 15 black wheat varieties were used as materials, and the farinograph parameters were measured by E-farinograph. At the same time, the effects of the ‘Zhouheimai1’ flour blending and ordinary wheat flour on the quality of steamed bun and bread were also analyzed. The results showed that the water absorption of the tested varieties was 57.4%-67.2%, the formation time was 2.7-7.8 min, the stability time was 2.3-10.8 min, the softness was 49-141 Fu, and the farinograph quality number (FQN) was 41-165. The water absorption of ‘Luozhen 1’, ‘Tesexiaomai 1’ and ‘Jiziheimai 9’ was higher than that of the control ‘Jimai 44’. The formation time, stability time and FQN of ‘Jiziheimai 9’ were higher than that of other varieties, which could be used as the key germplasm for strong gluten color wheat breeding. The stability time of 5 black wheat varieties, including ‘Shuzimai 1801’, was less than 3 min, which could be used as key germplasm for weak gluten color wheat breeding. The quality of steamed bun or bread was lower than that of ordinary wheat flour when it was blended with ‘Zhouheimai1’ flour. The optimal proportion of flour was different from previous studies. The purpose of this study is to provide reference for the formulation of color wheat quality evaluation standards, as well as to provide technical support for the promotion of color wheat and the industrialization development of related foods products.

To screen out the most efficient combination of control agents for the prevention and control of wheat diseases in the middle to late stages, 7 new agents such as 18.7% propyrimidin suspension（Yangsui） and 6 conventional agents such as 50% benzoyl propiconazole aqueous emulsion（Yingyue） were applied at jointing booting stage, heading and flowering stage and blooming stage, respectively, with no application of drugs as blank control. The prevention and control effects of Fusarium head blight in the middle to late stage of wheat were investigated, and the safety and yield of wheat were observed. The results showed that each treatment combination was safe for wheat growth under experimental doses, had good control on scab, powdery mildew and rust in the middle to later stages of wheat, and had good yield increase effect. Among them, the T₂ treatment (Jointing and booting stage used Yangsui 750 mL/hm²+ Licheng 300 mL/hm²+ Alika 150 mL/hm²+ Yishibang 750 mL/hm²; Heading and flowering used Maitian 900 mL/hm²+ Maitian partner 600 mL/hm²+ Alika 150 mL/hm²+ Yishiduojin 750 mL/hm²; Flowering used Maitian 900 mL/hm²+ Maitian partner 600 mL/hm²+ Yishiduojin 750 mL/hm²) had the best control effect and the highest wheat yield. In conclusion, different agents were used in the common areas of wheat Fusarium head blight could effectively control wheat disease and delay the development of its drug resistance.

Wheat basal rot is a disease that has occurred in wheat fields in recent years, particularly in corn-wheat continuous cropping fields, where it has shown a trend of increasing severity, causing a reduction in this plant yield and quality to some extent. To understand the occurrence characteristics of this disease and effectively control its spread and minimize damage, based on the wheat production practice in Lingbi County, Anhui Province, the occurrence, damage symptoms, disease characteristics, and influencing factors of this disease rot were analyzed through years of field investigations and a review of relevant literature. On this basis, the health cultivation as the basis were proposed, including the selection of resistant varieties, crop rotation, appropriate deep plowing, removal of straw from the field, precision seeding, and balanced fertilization. Additionally, seed treatment with chemicals during the wheat sowing period, the use of highly effective and low-toxicity pesticides for green control during the regreening stage, and an integrated control technology combining “one spray for three preventions” during the heading stage to manage wheat basal rot were recommended.

To study the soil carbon sequestration potential, a long-term monitoring site of wheat and maize double-cropping farmland in Xiangcheng County, Henan Province was selected as the research object. The Century model was used to simulate the dynamic change process of soil organic carbon during the monitoring period (2010-2023), and the applicability of the Century model was verified by comparing with the measured data. At the same time, one basic agricultural management measure and four optimized agricultural management measures were selected to simulate and predict the soil carbon sequestration potential in the next 20 years (2024-2043) by using the Century model. The simulation results showed that during the monitoring period, soil organic carbon density at the monitoring sites increased by 0.31 mg/hm² annually, showing a “carbon sink” status, mainly due to the increase of nitrogen fertilizer application rate. The results of Century model validation found that the model had good applicability in simulating and predicting the dynamic change of soil organic carbon. Under the condition of basic agricultural management measures, the soil carbon sequestration potential was low, and the state was weak and stable. Under the condition of agricultural management measures combining less tillage and 50% straw returning, the soil carbon sequestration potential was the highest, which was the most effective agricultural management measure. Therefore, the implementation and popularization of optimized agricultural management measures in the wheat and maize double-cropping farmland area of Henan Province is an important means to enhance soil carbon sequestration capacity, which is of great significance for alleviating greenhouse effect and realizing national food security.

In order to improve the utilization efficiency of farmland and increase the wheat yield per unit area, wheat sowing production experiment of the ‘wide sowing in narrow row’ was carried out through the transformation of the ‘narrow sowing in narrow rows’ wheat sower, and a designed experiment was conducted for checking the wheat yield change in 15 cm narrow row with sowing belt increased. The results showed that the ‘narrow sowing in narrow rows’ wheat sower’s opener could be transformed into the ‘wide sowing in narrow row’ sower’s opener, and the sowing belt increased from 2.6, 2.9 cm to 7.6 cm, and the area of the sowing belt increased by 176% on average. Within a limited row, the wheat yield per unit area increased with the increase of sowing belt width; the ‘wide sowing in narrow row’ yield increased by 11.3% to 17.3% than the ‘narrow sowing in narrow rows’. The direct cause of the yield increase per unit area of ‘wide sowing in narrow row’ is that the area per plant, the number and proportion of large plants increased, the number and proportion of small plants decreased, and the yield of small plants increased. ‘Narrow sowing in narrow row’ wheat sower needs to be reformed to improve the utilization efficiency of wheat land and develop efficient wheat farming.

To explore the effect of exogenous melatonin (MT) on the growth of wheat seedlings under cadmium (Cd)stress, this experiment took wheat of Womai 99 as the research object, and adopted the method of indoor temperature tank hydroponics to stress wheat with 100 µmol/L concentration of Cd. Leaf surface was sprayed with different concentrations of MT (0, 10, 100 and 1 000 µmol/L), and the plant height, fresh weight, dry weight, chlorophyll, SOD activity, POD activity and MDA content of wheat were measured respectivly. The results showed that under Cd stress, the plant height, fresh weight, dry weight, chlorophyll content, POD and SOD activities of wheat were increased, and the MDA content of wheat was decreased after different concentrations of MT were sprayed compared with blank control. In conclusion, under Cd stress, MT spraying could promote wheat growth and enhance the stress resistance of wheat seedlings, and 100 µmol/L MT had better effects on plant height, fresh weight, dry weight, chlorophyll content and SOD activity, and 1 000 µmol/L MT had better effects on increasing POD activity and decreasing MDA content.

Wheat straw resource utilization is one of the important ways to promote the sustainable development of agricultural production. Taken Anhui Province as an example, the current situation of wheat straw resource utilization, the practical significance of its forage utilization and the links to be further improved were analyzed, and the use pattern and strategies of wheat straw forage utilization were explored, to provide a reference for the efficient forage utilization of wheat straw resources. Wheat straw forage utilization showed a deepening transformation from traditional utilization to high-technology and high value-added direction. As an important direction of wheat straw resource utilization, forage utilization could not only effectively improve the utilization rate of resources, reduce the waste of resources and environmental pollution, but also help to improve the economic benefits of aquaculture, and its utilization ways mainly included sodium hydroxide treatment, ammoniation treatment, biological treatment and granulation technology, etc. At present, wheat straw forage utilization temporarily exist challenges such as nutritional value, digestibility, utilization efficiency and forage benefit to be further improved. Based on this, the effective measures to promote wheat straw forage utilization were analyzed from the economic level, supporting level, scientific research level, application level and technical level, and the development trend of wheat straw forage utilization in the future showed the characteristics of diversification and high technology.

Nitrogen application rate and base-topdressing ratios of nitrogen fertilizer are key factors affecting wheat yield. Different nitrogen application rate and base-topdressing ratios of nitrogen fertilizer have important effects on the number of tillers and yield components at different growth stages of wheat. Exploring the optimal combination of nitrogen application rate and base-topdressing ratios of nitrogen fertilizer can effectively improve wheat yield. A two-factor design was used in this study. Four different nitrogen application rates were set for the main treatment, including F₁ 120 kg/hm², F₂ 180 kg/hm², F₃ 24kg/hm² and F₄ 300 kg/hm². Six different base-topdressing ratios of nitrogen fertilizer were set for secondary treatment, including N₁ 3:7, N₂ 4:6, N₃ 5:5, N₄ 6:4, N₅ 7:3 and N₆ 10:0. Nitrogen topdressing was carried out at the jointing stage. The number of internal tillers was investigated at seedling stage, overwintering stage, jointing stage, booting stage and maturity stage. The 1000-grain weight was measured at the filling stage. Effective spike number, grain number per spike, and 1000-grain weight were measured at the maturity stage. The results showed that the yield of ‘Zhengmai 369’ was significantly affected by nitrogen application rate, base-topdressing ratios of nitrogen fertilizer, and their interaction. Among them, F₃ effectively increased the population number of wheat, F₂ reduced the tiller loss rate at the heading stage, and F₂ had the greatest effect on the yield of ‘Zhengmai 369’, increasing yield by 9.74%-33.58%. Wheat yield decreased with the increase of nitrogen fertilizer proportion in the base fertilizer. Compared with N₁, N₂ and N₃, wheat yield decreased significantly under N₅ and N₆. Under the interaction of nitrogen application rate and base-topdressing ratios of nitrogen fertilizer, F₂N₁ had the highest wheat yield, with a maximum increase of 52.12% compared to other treatments. The results showed that nitrogen application rate and base-topdressing ratios of nitrogen fertilizer affected the yield of ‘Zhengmai 369’ by affecting the effective spike number and 1000-grain weight. Among the treatments, the wheat yield under the interactive treatment of F₂N₁ reached the highest. This study provided an important theoretical basis for optimizing high-yield cultivation measures of ‘Zhengmai 369’.

The aim was to explore the effects of different new urea on yield and nitrogen uptake and utilization of winter wheat-summer maize rotation system in the North China Plain, with a view to providing a theoretical basis for the application of new urea in practical production. Using common urea as a control, six new types of urea were applied for 5 consecutive years to measure the yield of wheat-maize rotation, analyze the effect of new urea on the composition of the yield, and at the same time, determine the nitrogen uptake of plants and seeds, and account for the nitrogen fertilizer agronomic efficiency, bioproductivity, and production benefits of the new types of urea. The results showed that compared to the ordinary urea, continuous application of the new urea all significantly increased the yield of wheat-maize rotation system (P<0.05), with the range of yield increase from 7.08% to 11.77%, of which 9.02% was increased by the loss-control urea in the wheat season, and 15.52% was increased by the zinc-containing urea in the maize season; there was no significant difference in nitrogen absorption and utilization of the new urea during the wheat season, while the average nitrogen fertilizer agronomic efficiency of loss-control urea fertilization and zinc containing urea in the corn season reached 9.49 kg/kg and 10.63 kg/kg, respectively. From the perspective of production efficiency, the net benefit of using loss-control urea in batches and zinc (manganese) containing urea was the highest. Under the conditions of this experiment, it was recommended to apply loss-control urea or zinc (manganese) containing urea in the winter wheat-summer corn rotation system in the North China.

【Objective】Taikemai33, derived from a cross between Zhengmai366 and Huaiyin9908, is a new released wheat cultivar with high quality, high yield, and excellent disease resistance, which has a broad genetic base, and a high potential for application in wheat production. The objective of this study is to dissect the genetic composition of Taikemai33 to provide information for parental selection to use this cultivar to develop more new wheat cultivars. 【Method】Taikemai33 and its pedigree parents including Zhengmai366, Huaiyin9908, Yumai47, PH82-2-2, Yumai13, Yumai 2 hao, Bainong3217, Yanda24, Xiannong39, Fengchan 3 hao and Funo were screened using the 55K wheat SNP chip to dissect the genomic composition of Taikemai33 to evaluate the genetic contributions of each parental line to Taikemai33. 【Result】The similarity coefficient between Taikemai33 and its pedigree parents ranged from 0.72 to 0.93, and the genetic composition of Taikemai33 was highly similar to Zhengmai366, the pedigree mother parent, with a genetic similarity coefficient of 0.93. SNP marker analysis showed that the pedigree parents contributed different proportion to the genome of Taikemai33, with the pedigree mother contributed 66.57%, whereas the pedigree father contributed 33.43%, indicating that Taikemai 33 inherits more genetic materials from the maternal lineage. Furthermore, the pedigree mother contributed 71.0%, 85.0% and 49.4% to subgenome A, B and D of Taikeimai33, whereas those were 29.0%, 15.0% and 50.6% contributed by the pedigree father. For each chromosome, the pedigree mother contributed more on chromosome 1A, 2A, 3A, 4A, 7A, 1B to 7B, 1D and 2D, whereas the pedigree father contributed more on chromosome 5A, 4D, 6D and 7D. The contributions of the pedigree parents on 6A, 3D and 5D were equal. Taikemai33 genotype map showed that the contribution loci of the pedigree mother were distributed in clusters on chromosome 1A, 5A, 7A, 2B, 7B, 2D, with those from the pedigree father were on chromosome 4A, 5A, 6D, 7D. Interestingly, among the polymorphic SNP loci, between Zhenmai366 and Huaiyin9908, Taikemai33 showed 109 loci that were absent in both parents, distributing on 19 chromosomes except 1A and 6A. Chromosome 4A, 2B, 6B and 7D of Taikemai33 confer most of the polymorphic SNPs in clusters with cluster number of 10, 9, 11, and 9. 【Conclusion】We constructed the genotype map and dissected the genetic composition of Taikemai33, determined the loci contributed by the pedigree parents and identified that Taikemai33 inherited more genetic materials from the pedigree mother and conferring some specific loci different with the pedigree parents.

【Objective】The purpose of this study was to determine the effects of nitrogen application amount on the yield composition, economic benefit of summer sowing intercropping crops and the yield of winter wheat. 【Method】From 2022 to 2023, the representative farmlands were selected in Yucheng City, Shandong Province, which was the main extension area of maize-soybean strip intercropping. Maize monoculture (Nitrogen application rate: 225 kg·hm^-2), soybean monoculture (Nitrogen application rate: 45 kg·hm^-2), maize-soybean intercropping with full nitrogen application (Nitrogen application rate: 270 kg·hm^-2), maize-soybean intercropping with reduced nitrogen application (Nitrogen application rate: 135 kg·hm^-2) were set up in summer sowing season, and the subsequent crops were planted with wheat without fertilizer treatment. The effects of different summer sowing treatments on photosynthetic characteristics, agronomic traits, economic benefits and yield of subsequent wheat were analyzed. 【Result】Both planting pattern and nitrogen application amount had significant effects on crop growth and development. Compared with maize monoculture, the chlorophyll content, P_n, G_s, C_i and T_r of maize leaves were significantly decreased by intercropping reduced nitrogen application (135 kg·hm^-2). However, the P_n, G_s and T_r of leaves of intercropping full nitrogen maize (270 kg·hm^-2) were significantly increased by 8.8%, 10% and 11.6%, respectively. Intercropping system resulted in decreased chlorophyll content of soybean, inhibited leaf P_n, G_s, and T_r. In terms of agronomic characteristics, stem length increased, pod number per plant decreased, and yield decreased by 65.1%-68.4%. There was no significant difference in the agronomic characteristics and yield of maize under the intercropping system with full nitrogen application, and the economic benefit was the highest under this system, reaching 22 607 yuan/hm², while the agronomic characteristics such as ear length, grain number per ear and hundred-grain weight of maize under reduced nitrogen application significantly decreased, and the yield decreased by 14.8%. However, in general, the land equivalent ratio of both maize and soybean treatments was also greater than 1. Economic benefit and nitrogen uptake were increased by 4.8%-11.5% and 19.7%-38% compared with monocrop. When winter wheat was not fertilized, the grain yield and crop nitrogen uptake of aftercrop winter wheat with full nitrogen application in summer sowing were higher than that under other treatments, and there was no significant difference between the yield of winter wheat with reduced nitrogen application between summer sowing seasons and that of winter wheat with summer sowing maize. 【Conclusion】Therefore, from the comprehensive analysis of agronomic characteristics, yield and economic benefits as well as the effects on aftercrop, the effect of total nitrogen application in intercropping was better than that of reduced nitrogen application in intercropping. However, considering the yield, economic and environmental benefits, the amount of nitrogen application in intercropping should be further optimized.

【Objective】To clarify the effects of catch crop decomposition liquid on the growth and blight of continuous pepper seedlings, and to provide the theoretical basis and technical support for wheat and broad bean catch crop to alleviate the continuous cropping obstacles of peppers. 【Method】 Pepper and pepper continuous cropping soil were used as the research object. Firstly, seven catch crop treatments were set up, including wheat (A), broad bean (B), large-leafed skunk cabbage (C), wheat and broad bean mixture (AB), wheat and large-leafed skunk cabbage mixture (AC), broad bean and large-leafed skunk cabbage mixture (BC), and wheat, broad bean and large-leafed skunk cabbage mixture (ABC), and the non-catch crops were used as the control (CK). Study the effects of different treatments on the pepper growth and blight. Secondly, in order to ascertain the role of its catch crop decomposition liquid in promoting growth and disease control, four treatments with different concentrations of wheat and broad bean mixture straw decomposition liquid (0.01, 0.03, 0.05, and 0.07 g·mL^-1) were set up to investigate different treatments the effects on the growth and blight of pepper seedlings, using distilled water as the control (CK). 【Result】 When transplanting for 20 and 30 d, the fresh weight of the whole plant, dry weight of the whole plant and plant height of pepper after mixed catch crop treatment of wheat and broad bean were significantly higher than those no-catch crops treatments, and the incidence and disease index were significantly lower than those no-catch crops treatments. The disease index of the wheat and broad bean mixed catch crop treatment was significantly lower than that of all other treatments. The whole plant fresh weight of pepper was significantly increased at 20 d and 30 d of treatment with wheat and broad bean mixed straw decomposed liquids. At 30 d, the dry weight of the whole pepper plant was significantly increased except for 0.01 g·mL^-1 treatment. Compared with distilled water treatment, 0.03 g·mL^-1 treatment significantly increased the root length, average diameter of roots, root surface area, root volume, root tip number and leaf peroxidase (POD) and polyphenol oxidase (PPO) activities of pepper (P<0.05). The mycelial diameter, zoospore germination rate and sporulation yield of Phytophthora capsici treated with different concentrations of wheat and broad bean mixture straw decomposed liquids were significantly lower than those of distilled water treatment (P<0.05). The mycelial diameter and zoospore germination rate of 0.03 g·mL^-1 treatment were significantly lower than those of other treatments, and the inhibition effect of 0.03 g·mL^-1 treatment on phytophthora blight and blight was the best. 【Conclusion】The mixed catch crop of wheat and broad bean had a growth-promoting and disease-inhibiting effect on continuous cropping pepper seedlings, and its straw decomposed liquids played an important role in which the decomposed liquids concentration of 0.03 g·mL^-1 when the best effect, and its role was closely related to the direct inhibition of the phytophthora blight and improved the activity of the plant defense enzymes.