施肥对苜蓿土壤水分、养分和产量的影响:基于定位试验数据的Meta分析

为探究提高苜蓿(Medicago sativa)产量和改善土壤肥力性质的施肥措施,本研究以中国为研究区域,以不施肥苜蓿为对照,通过检索文献整合已发表的相关田间试验数据,采用整合分析方法(Meta-analysis),系统探究施肥措施对苜蓿地土壤水分、养分、产量和水分利用效率的影响.结果表明,施肥可有效增加苜蓿土壤养分含量并提高苜蓿产量,但增加的地上生物量也影响了苜蓿对土壤水分的消耗,其中土壤有机质和全氮含量分别增加了3.1％～33.3％和4.5％～30.9％,土壤速效磷和速效钾含量分别提高了3.6％～144.4％和4.4％～24.8％,土壤水分下降了4.4％～11.8％.与不施肥相比,施肥措施下苜蓿增产率达到15.4％～198.2％,水分利用效率提高了5.9％～169.6％.进一步相关分析表明,苜蓿产量与0-200 cm土壤水分、有机质和速效磷含量均呈极显著正相关关系(P<0.01),苜蓿水分利用效率与土壤速效磷含量呈极显著正相关关系(P<0.01).综上,施肥可有效增加土壤养分含量并提高苜蓿产量,其中化肥和有机肥配施表现出的增产作用最为突出,化肥配施对苜蓿水分利用效率的提升效应最佳.该研究可为苜蓿种植过程中适宜施肥措施的选择提供理论依据.

Meta-analysis on response of soil moisture,nutrients, and alfalfa yield to fertilization based on location test data

Alfalfa (Medicago sativa) is an important forage crop for livestock feed that contributes nitrogen to succeeding crops in crop-rotation systems. A meta-analysis was conducted to determine how fertilization strategies affected forage yield and soil fertility of alfalfa fields in China. Non-fertilizer was used as control treatments in this research. Based on the published data of relevant location test and the meta-analysis, the quantitative effects on fertilizer application on alfalfa with respect to soil water content, nutrients, yield, and WUE were studied. The results showed that fertilization could improve soil nutrients and alfalfa yield, whereas an increase in alfalfa biomass resulted in a decrease in soil water content. Fertilization increased soil organic matter and nitrogen by 3.1% ~ 33.3% and 4.5% ~ 30.9%, respectively. Similar trends were observed with respect to soil available phosphorus and available potassium, which increased by 3.6% ~ 144.4% and 4.4% ~ 24.8%, respectively. However, owing to the increase in alfalfa biomass, the soil water content decreased by 4.4% ~ 11.8%. As a result, the alfalfa yield and WUE improved by 15.4% ~ 198.2% and 5.9% ~ 169.6%, respectively. Correlation analysis showed that the alfalfa yield was positively correlated with soil water content at 0 – 200 cm, organic matter and available phosphorus; the WUE of alfalfa was positively correlated with soil available phosphorus. In conclusion, fertilization could improve soil nutrients as well as alfalfa yields. The combined application of organic and inorganic fertilizers is an optimum strategy for increasing alfalfa yields, while the combined application of N, P, and K fertilizers is better for WUE. These findings can provide a strategy for farmers to enhance the sustainability of the alfalfa system through fertilization management.