Abstract
Green manure legumes represent an important nitrogen (N) source potentially reducing the need for fertilizer inputs. Organic vegetable production systems, which aim to reduce reliance on external N sources, require enhanced control over legume-derived N and high transfer efficiency, with which this N contributes to the N supply for vegetable crops. The primary objective of the study was to quantify the N fertilizer value of cut green manure herbage transferred to vegetable crops and to evaluate residual effects on subsequent cereal crops. During four field experiments, the apparent net N mineralization of soil incorporated and surface mulched cut-and-carry biomass differing in nutrient composition and application rate ranged from 6 to 39% and from 4 and 27% within the year of their application, respectively. Despite a positive response of mulch N mineralization to application rate, the highest short-term N release was observed for soil incorporated herbage with low C:N ratio, being potentially comparable to that of organic N fertilizers. Net residual N effects on subsequent cereal crops averaged 5.2 and 5.3% for soil incorporated and mulched herbage biomass respectively, and did not compensate for low N mineralization rates in the year of application. Ensiled herbage exhibited low short-term N mineralization rates not exceeding 9%, limiting its potential to replace organic N fertilizers for early-season vegetable crops. Thus, a significant challenge arises from the lack of timely synchronicity between biomass availability and vegetable cropping periods, constraining efforts to reduce reliance on external N sources.
Abstract
Green manure legumes represent an important nitrogen (N) source potentially reducing the need for fertilizer inputs. Organic vegetable production systems, which aim to reduce reliance on external N sources, require enhanced control over legume-derived N and high transfer efficiency, with which this N contributes to the N supply for vegetable crops. The primary objective of the study was to quantify the N fertilizer value of cut green manure herbage transferred to vegetable crops and to evaluate residual effects on subsequent cereal crops. During four field experiments, the apparent net N mineralization of soil incorporated and surface mulched cut-and-carry biomass differing in nutrient composition and application rate ranged from 6 to 39% and from 4 and 27% within the year of their application, respectively. Despite a positive response of mulch N mineralization to application rate, the highest short-term N release was observed for soil incorporated herbage with low C:N ratio, being potentially comparable to that of organic N fertilizers. Net residual N effects on subsequent cereal crops averaged 5.2 and 5.3% for soil incorporated and mulched herbage biomass respectively, and did not compensate for low N mineralization rates in the year of application. Ensiled herbage exhibited low short-term N mineralization rates not exceeding 9%, limiting its potential to replace organic N fertilizers for early-season vegetable crops. Thus, a significant challenge arises from the lack of timely synchronicity between biomass availability and vegetable cropping periods, constraining efforts to reduce reliance on external N sources. Leer más
Related posts:
Soil nitrogen dynamics affected by coffee (coffea arabica) canopy and fertilizer management in coffee-based agroforestry
Early‐season biomass and weather enable robust cereal rye cover crop biomass predictions
Cover crop management strategies affect weeds and profitability of organic no-till soybean
Soil health indicators reveal that past dairy manure applications create a legacy effect
A new approach for modelling weed suppression of cover crops
Onion quality and yield after agronomic biofortification with selenium