新疆几种禾本科牧草对土壤氮素的影响

试验比较了紫花苜蓿、春小麦与冰草、牛尾草、老芒草和无芒雀麦等禾本科牧草对种植土壤氮素的影响。种植春小麦一年后,使土壤全氮含量每盒减少0.85g,降低了5.33%。而种植紫花苜蓿、冰草、牛昆草、老芒麦和无芒雀麦等牧草一年后,分别使每盆土壤增加氮3.56、1.51、1.24、0.93和0.51g,士壤含氮量分别提高22.15、9.39、7.73、5.79和3.19%。种植土壤所增加的氮中碱解氮所占比例,分别由种植前土壤的6.46%提高到6.81、7.58、8.00、8.33和8.37%。禾本科牧草使种植土壤中增加的氮产物更易为农作物吸收利用,土壤供氮强度为种植紫花苜蓿后的3—6倍,而种植春小麦一年后土壤碱解氮含量未见显著性变化。

The Contribution to N in Soil by Some Gramineae Forage Grasses Native in Xinjiang

A compare exerperiment on the contribution to N in potting soil from a field of grass and crop rotation among native alfalfa, wheatgrass, tall fescue, Siberian wildry, awnless brome and spring wheat was conducted in Xinjiang. One year after planting spring wheat, there was a decrease of 0.85gN/pot or 5.33% to total N in potting soil but registed an insreaseof 3.56, 1.51, 1.24, 0.93 and 0.51 gN/pot or 22.15, 9.39, 7.73, 5.79 and 3.19% to total N one year after planting alfalfa, wheatgrass, tall fescue, Siberian wildry, and awnless brone separately. All the forage grass on the trial could raise hydrolysis N and as same as the totaal N, there was a much greater species variation in increase of hydrolysis N among the forage grassess. One year after planting, alfalfa, Siberian wildry, wheatgrass, awnless brome and tall fescue cuulu make the potting soil an increase of hydrilysis N of 0.30, 0.38, 0.37, 0,35 and 0.27 gN/pot or 28.82, 36.47, 35.55, 33.67 and 26.51%, The rtate of hydrolysis N to total N in potting soil was raised from 6.46% to 6.81, 7.58, 8.07,8.33 and 8.30% for alflafa, tall fescue whatgrass, Siberian wildry and awnless brome separately. There was no change of hydrolysis N in potting soil one year after planting spring wheat. The rate of hydrolysis N to total N is 6.1, 7.2, 13.7 and 24.8 times as that caused by akfalfa for tall fescue, wheat grass, Siberian wildry and a wnless brome separately. The increased N in soil by cereal forage grass is used mueh easier than those resulted from alfalfa.