Environment and Sustainable Resource Management Section, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland.
Agricultural Economics and Farm Surveys Department, Rural Economy & Development Centre, Teagasc, Mellows Campus, Athenry, Ireland.
Sci Total Environ. 2020 Jun 10;720:137245. doi: 10.1016/j.scitotenv.2020.137245. Epub 2020 Feb 12.
Agriculture faces considerable challenges of achieving more sustainable production that minimises nitrogen (N) and phosphorus (P) losses and meets international obligations for water quality and greenhouse gas emissions. This must involve reducing nutrient balance (NB) surpluses and increasing nutrient use efficiencies (NUEs), which could also improve farm profitability (a win-win). To set targets and motivate improvements in Ireland, nationally representative benchmarks were established for different farm categories (sector, soil group and production intensity). Annual farm-gate NBs (kg ha) and NUEs (%) for N and P were calculated for 1446 nationally representative farms from 2008 to 2015 using import and export data collected by the Teagasc National Farm Survey (part of the EU Farm Accountancy Data Network). Benchmarks for each category were established using quantile regression analysis and percentile rankings to identify farms with the lowest NB surplus per production intensity and highest gross margins (€ ha). Within all categories, large ranges in NBs and NUEs between benchmark farms and poorer performers show considerable room for nutrient management improvements. Results show that as agriculture intensifies, nutrient surpluses, use efficiencies and gross margins increase, but benchmark farms minimise surpluses to relatively low levels (i.e. are more sustainable). This is due to, per ha, lower fertiliser and feed imports, greater exports of agricultural products, and for dairy, sheep and suckler cattle, relatively high stocking rates. For the ambitious scenario of all non-benchmark farms reaching the optimal benchmark zone, moderate reductions in farm nutrient surpluses were found with great improvements in profitability, leading to a 31% and 9% decrease in N and P surplus nationally, predominantly from dairy and non-suckler cattle. The study also identifies excessive surpluses for each level of production intensity, which could be used by policy in setting upper limits to improve sustainability.
农业在实现可持续生产方面面临着相当大的挑战，需要最大限度地减少氮（N）和磷（P）的流失，并履行国际水质和温室气体排放义务。这必须涉及减少养分平衡（NB）盈余，提高养分利用率（NUE），这也可以提高农场的盈利能力（双赢）。为了设定目标并促进爱尔兰的改进，为不同的农场类别（部门、土壤组和生产强度）制定了具有代表性的全国基准。使用 Teagasc 国家农场调查（欧盟农场会计数据网络的一部分）收集的进出口数据，计算了 2008 年至 2015 年 1446 个具有代表性的全国性农场的年度农场门口 NB（kg/ha）和 N 和 P 的 NUE（%）。使用分位数回归分析和百分位排名为每个类别建立基准，以确定每个生产强度下 NB 盈余最低和总利润（€/ha）最高的农场。在所有类别中，基准农场和表现较差的农场之间的 NB 和 NUE 差异很大，表明在养分管理方面有很大的改进空间。结果表明，随着农业集约化程度的提高，养分盈余、利用率和总利润增加，但基准农场将盈余降至相对较低的水平（即更具可持续性）。这是由于每公顷的化肥和饲料进口减少，农产品出口增加，以及奶牛、绵羊和奶牛的存栏率相对较高。对于所有非基准农场都达到最佳基准区域的雄心勃勃的情景，发现农场养分盈余适度减少，盈利能力大幅提高，导致全国 N 和 P 盈余分别减少 31%和 9%，主要来自奶牛和非奶牛。该研究还确定了每个生产强度水平的过量盈余，政策可以利用这些盈余来设定上限，以提高可持续性。
