TY - JOUR T1 - Evaluating Optimum Nitrogen Management Associated with Production and Environmental Load of Farm-Systems in the Dahuofang Reservoir Region AU - , Lei Liang AU - , Ning Hu AU - , Da Tian Jin AU - , Lu Lu Zhao JO - Environmental Research Journal VL - 2 IS - 5 SP - 265 EP - 270 PY - 2008 DA - 2001/08/19 SN - 1994-5396 DO - erj.2008.265.270 UR - https://makhillpublications.co/view-article.php?doi=erj.2008.265.270 KW - Agricultural systems KW -N balance KW -N Cycling index KW -N management AB - N budgets analysis model offers a new set of tools for evaluating the N cycling in Agricultural systems. Cycling Index (CI) is also a useful tool for estimating optimal N flows in farms and Application Index (AI) as a good indicator for characterizing the N flows in farms. Using these parameters, we analyzed all farm-systems to estimate the optimal N Management for safety N pollution in ground water and maximizing N export in the Dahuofang Reservoir region. It was clearly shown the critical N application rate (chemical fertilizer + manure) was 208.4 kg N ha 1 y 1. The critical inter-system input (application N, imported food and feed N and natural supplied N) was 422.5 kg N ha 1 y 1. ER -