施肥对紫花苜蓿产量的影响

在青海大通县长宁地区采用四因素二次通用旋转组合设计,研究氮、磷、钾、硫肥的施用效果.结果表明:在该地区,随着氮、磷、钾、硫施用量的增加,苜蓿产量先增后减.施用量的最优组合为尿素225 kg/hm2,过磷酸钙675 kg/hm2,加拿大钾肥225 kg/hm2,硫磺粉15 kg/hm2.在低氮时,苜蓿产量随磷肥用量增加而增加,随钾肥用量的增加而先增后减;在高氮情况下,产量随磷肥用量先增后减,随钾肥用量增加而增加.在低磷的情况下.产量随氮肥用量增加而增加;在高磷情况下,随氮肥用量的增加产量变化不大,磷、钾配合,在一个因素固定后,另一因素随着施肥水平的增加苜蓿产量先增后减.在低磷条件下,增加硫肥的施肥量,苜蓿产量先增后减,在高磷条件下,增加硫肥施肥量的苜蓿产量逐渐增加.

The influence of fertilizer to the yield of Medicago sative L.

The 4 factors and quadratic general rotary unitized design molybdenum trial are carried out at Changning area of Datong county to find out the effect of nitrogen,phosphorus,potassium and sulphur on Medicago sative L..The result showed that,as the increasing of nitrogen,phosphorus,potassium dosage,the yield of Medicago sative L.increases at first and then decreases.The best fertilizer combination is urea 225 kg/hm2,calcium super phosphate 675 kg/hm2,Canadian potassium 225 kg/hm2,suphur 15 kg/hm2.At lower nitrogen soil,the Medicago sative L.yield increases as the increasing of phosphorus dosage,but it increase at first and then decrease as the increasing of potassium;at higher phosphors soil,there is not any obviously change as nitrogen increasing,it increases as potassium increasing.At higher phosphors soil,the yield don't change obviously as nitrogen increasing,while the combination of nitrogen and phosphorus fixed at certain level,the yield of Medicago sative L.increases at first and then decreases as another fertilizer factor increasing;at lower phosphorus soil,the yield of Medicago sative L.increases at first and then decreases as sulphur increasing,at higher phosphorus,the phosphorus increases gradually as sulphur increasing.