我国主产区紫花苜蓿营养状况分析

The nutrient situations in the major alfalfa producing areas of China

为探究我国主产区紫花苜蓿营养现状以及生产中肥料使用的科学性,2012年5 6月,对我国紫花苜蓿主产区21个大田样地苜蓿初花期时的土壤养分、植物组织营养以及第一茬产草量和施肥管理情况进行测定和调研,对土壤和植物营养状况进行评价,对土壤和植物养分含量与产草量间的关系进行了分析。研究表明,紫花苜蓿主产区土壤以砂性为主,有机质含量低。紫花苜蓿组织中氮素营养处于充足水平,磷素(P)和钾素(K)普遍缺乏,微量元素中锌(Zn)、硼(B)、钼(Mo)元素缺乏。土壤中磷素和植物体内硼(B)、钼(Mo)和铁(Fe)含量与第一茬产草量显著正相关。施用氮肥地块有12个,磷肥有5个,钾肥有3个,没有有针对性施用微量元素肥料的地块。建议在紫花苜蓿大田生产上控制氮肥施用,注重P、K肥的施用,有针对性地施用B、Mo等微量元素。

In order to clarify the availability of soil nutrients and the nutrition situation of alfalfa plants （Medicago sativa） in the major alfalfa producing area in China, soil and plant tissue samples were collected in 21 areas, the nutrient levels in both the soils and plant tissues in the early flowering stage of alfalfa were analyzed, and the first harvesting yields of grass and the reasonability of present fertilization were investigated from May to June 2012. The relationship between the nutrient supply and the yields was evaluated at the same time. The results show that the major alfalfa producing areas are mainly sandy soils with low levels of organic matter contents. The nitrogen （N） nutrition in alfalfa is sufficient, but phosphorus（P） and potassium（K） are inadequate in general, and trace elements such as zinc（ Zn）, boron （B）and molybdenum（Mo） are often deficient. The P in soils, B, Mo and Fe contents in plant tissues are significant and positively correlated with the yield of the first harvesting （ P 〈 0. 05 ）. Among the investigated fields, N fertilizers are applied in 12, P fertilizers in 5 and K fertilizers in 3 sites. Therefore, applications of P and K and trace elements B and Mo fertilizers should be taken as an effective way for the yields increase of alfalfa.