Effects of Applying Different Organic Materials on Grain Yield and Soil Fertility in a Double-Season Rice Cropping System

Double-cropping rice cultivation reduces soil fertility, and the extensive use of chemical fertilizers has harmful effects on both environment grain yield. The application organic materials could be used as a practical strategy to maintain fertility improve yield in double-season cropping system. For this purpose, field experiments with six growing seasons over three years, from 2016 2018, were conducted assess five (biochar, Chinese milk vetch, straw, rapeseed cake fertilizer, manure) aiming save about 25% nitrogen (N) fertilizer required for all stages. result showed that, compared CK (the most common dose study region; 100% without fertilizer), double-cropped increased after applying consecutive years. Specifically, CRC treatment (Chinese vetch (10.77 t ha−1 fresh)/rice straw (26.51 fresh) + 75% fertilizer) significantly higher rates effective panicles (4.65–10.92%) annual (8.00–8.82%). total N, phosphorus (P), potassium (K), alkaline available P content by 11.85%, 12.22%, 15.08%, 23.32%, 41.04%, respectively, relative CK. decomposition applied combined resulted more humus (9.50 g kg−1), humic acid (3.19 fulvic (3.26 active carbon (5.78 kg−1) pool management index (13.5%), well urease activity (18.10%) phosphatase (17.64%). Therefore, study, early season/rice late season was optimal It yields potential sustainable fertility.