Agro-ecosystem & Environment
GAO Peng, ZHANG Tuo, LEI Xing-yu, CUI Xin-wei, LU Yao-xiong, FAN Peng-fei, LONG Shi-ping, HUANG Jing, GAO Ju-sheng, ZHANG Zhen-hua, ZHANG Hui-min
Fertilization is an effective technique to improve soil fertility and increase crop yield. The long-term effects of different
fertilizers on soil considerably vary. Over 38 consecutive years of different fertilization positioning experiments in a
double cropping rice field of Qiyang Red Soil Experimental Station, seven different fertilization treatments including CK
(no fertilization), NPK (nitrogen, phosphorus, and potassium fertilizer), M (cow manure), NPKM (nitrogen, phosphorus,
and potassium with cow manure), NPM (nitrogen and phosphorus with cow manure), NKM (nitrogen and potassium
with cow manure), and PKM (phosphorus and potassium with cow manure) were applied to study the effects on rice
yield, soil fertility, and nutrient apparent balance in a paddy field. The results showed that the annual average yields of
rice in NPKM, NPM, NKM, PKM, M, NPK and CK treatments ranged from 6 214 to 11 562 kg ha–1. Yields under longterm
organic and inorganic treatments (NPKM, NPM, NKM and PKM) were 22.58, 15.35, 10.53 and 4.41%, respectively,
greater than under the NPK treatment. Soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN) and
available potassium (AK) concentration with long-term organic and inorganic treatment (NPKM, NPM, NKM and
PKM) were significantly higher than in inorganic fertilizer (NPK) treatments. Soil total phosphorus (TP) and available
phosphorus (AP) contentration with organic fertilizer combined with inorganic N and P fertilizer treatment (NPKM,
NPM and PKM) were significantly higher than with inorganic fertilizer alone (NPK treatments). The average annual
rice yield (11 562 kg ha–1), SOC (20.88 g kg–1), TN (2.30 g kg–1), TP (0.95 g kg–1), TK (22.50 g kg–1) and AP (38.94 mg
kg–1) concentrations were the highest in the NPKM treatment. The soil AN concentration (152.40 mg kg–1) and AK
contentration (151.00 mg kg–1) were the highest in the NKM treatment. N and P application led to a surplus of nitrogen and phosphorus in the soil, but NPKM treatment effectively reduced the surplus compared with other treatments.
Soils under all treatments were deficient in potassium. Correlation analysis showed that SOC, TN, AN, TP, and AP
contentration was significantly correlated with rice yield; the correlation coefficients were 0.428, 0.496, 0.518, 0.501, and
0.438, respectively. This study showed that the combined application of N, P, and K with cow manure had important
effects on rice yield and soil fertility, but balanced application of N, P, and K with cow manure was required.