苜蓿质量预测方法研究进展

苜蓿(Medicago sativa)质量是影响苜蓿干草价格的重要因素,而适时收获是把握苜蓿干草质量的重要环节。在科学种植管理条件下,对田间苜蓿质量提前判断,对准确收获目标质量苜蓿干草、保证经济效益意义重大。苜蓿产业较为发达的美国常用GDD和PEAQ法来预测田间苜蓿质量,以判断春季苜蓿的收获时间。当GDD为700～750时(5℃以上积温),苜蓿的NDF含量接近40%,当GDD增加220(7d后),NDF含量达到45%;PEAQ法中指出,NDF和ADF含量可以通过在具有随机样方中茎秆最高植株的茎长测量和判断样方中最成熟植株的成熟度来预测。GDD和PEAQ法对杂草较少、长势健康的苜蓿田生产质量预测比较准确。

The methods of predicting alfalfa quality in the field

Quality is a very significant factor that affects the alfalfa hay price.Harvesting at optimal time is a critical way to obtain high quality hay.With the scientific cultivating,predicting the quality of standing alfalfa in field is important to harvest the targeted quality hay and improve the farmers’ profit.In the alfalfa industry developed countries,such as USA,GDD(Growing degree-days)and PEAQ(Predictive Equations for Alfalfa Quality) are usually used to predict the quality of standing alfalfa,and determine the optimal harvesting time at spring.Some related researches showed that alfalfa with averages 40% NDF is at 700~750 GDD(base 5 ℃).It takes about 220 additional GDD to reach 45% NDF at GDD(base 5 ℃).With the PEAQ method,NDF and ADF could be accurately determined in field by measuring height of the tallest stem and maturity of the most mature stem in a sample area.The GDD and PEAQ would be predicted accurately under the situation of the alfalfa field grows well and contains little weeds.