Exploring site-specific N application rate to reduce N footprint and increase crop production for green manure-rice rotation system in southern China.

Milk vetch (Astragalus sinicus L.) is leguminous green manure (GM) which produces organic nitrogen (N) for subsequent crops and is widely planted and utilized to simultaneously reduce the use of synthetic N fertilizer and its environmental costs in rice systems. Determination of an optimal N application rate specific to the GM-rice system is challenging because of the large temporal and spatial variations in soil, climate, and field management conditions.

[Effects of Chinese Milk Vetch Returning Incorporated with Chemical Fertilizer Reduction on the Composition and Function of Soil Bacterial Communities in Paddy Fields].

Chinese milk vetch ( L.) is an important organic nutrient resource in the southern Henan rice-growing area. Thus, the effects of Chinese milk vetch (MV) returning incorporated with reduced chemical fertilizer on the physicochemical properties and bacterial community characteristics in paddy soil were studied.

[Effects of combined with chemical fertilizer on nitrogen absorption and utilization of rice and nitrogen distribution and residue of in rice-soil system].

Clarifying the pattern of nitrogen absorption and utilization of rice under the treatments of combined with chemical fertilizer application and the pattern of absorption, utilization, distribution and residue of nitrogen in rice-soil system could provide basis to rational fertilization for rice planting area in southern Henan. In this study, undisturbed soil column simulation and isotope tracer technology of N were used to examine the differences of nitrogen uptake and utilization of rice, nitrogen nutrient balance of rice-soil system and nitrogen uptake, utilization, distribution and residue of nitrogen after mineralization and decomposition among seven treatments. The treatments involved 1) no fertilization (CK); 2) chemical fertilizer+22500 kg·hm (FM1); 3) chemical fertilizer+30000 kg·hm (FM2); 4) chemical fertilizer+37500 kg·hm (FM3); 5) chemical fertilizer+22500 kg·hm +lime (FM1+CaO); 6) chemical fertilizer+30000 kg·hm lime (FM2+CaO); 7) chemical fertilizer+37500 kg·hm +lime (FM3+CaO).

[The characteristics of decomposition and nutrient release of Vicia villosa under different fertilization treatments.].

The effects of three fertilization treatments (no fertilizer, nitrogen fertilizer, and lime) on the characteristics of Vicia villosa decomposition and nutrient release were studied using the nylon bag method in the fields. The results showed that the cumulative decomposition rate of V. villosa was 65.