云南亚热带湿热地区豆科牧草定植需肥量初探

PRELIMINARY STUDY ON FERTILIZER APPLICATION RATES FOR ESTABLISHING LEGUME PASTURES IN SUB—TROPICAL HUMID—WARM AREAS OF YUNNAN PROVINCE

为了摸清亚热带湿热地区草场改良过程中的定植需肥量,从1987年开始进行豆科牧草的定植需肥量试验,通过对思茅曼中田几个点的土壤分析,1987年的温室盆栽试验和1988～1990年的小区试验结果表明:曼中田土壤中影响豆科牧草生长的主要因素为大量元素磷(P)和微量元素铜(Cu)与钼(Mo)。土壤分析结果表明:缺乏铜、锰(Mn)。大量元素硫(S)和钾(K)对豆科牧草的生长无明显影响。当钙镁磷(Ca—Mg—P)施用量达200～300公斤/公顷时,牧草产量随石灰用量的增加而下降,反产生逆效应。仅当钙镁磷用量低于100公斤/公顷时,加施一定量的石灰才能发挥正效应,以使产草量得以提高。

This study aims at obtaining fertilizer application rates for the pasture establishment in the subtropical humid—warm areas. Trials have been undertaken on pastures since 1987. After analyzing soils from different sites, pot trials in greenhouse in 1987 and field experiments in 1988～1990 were conducted at ManZhongtian Farm. The resuls showed that P, Cu and Mo. are the main elements affecting legume growth in favourable situation. This was supported by the soil chemical analysis in the Lab. It was also found that the soil contained the large amount of S and K. These two elements, however, did not much affect legume growth, when Ca—Mg—P were used at the rate of 200～300kg/ha, the yield of pastures decreased as lime rates increased in the experiment. When Ca—Mg—P was used at the lower rate of 100kg/ha, the certain amount lime application was necessary for increasing the pasture yield.