大麦的氮肥效应及改土效果初报

Response to nitrogen and effect on salty soil reclamation of barley(primary report)

大麦属耐盐性作物。它既能适应于盐渍土上生长,又可有脱盐改土的作用。种植三年水稻后的盐渍土通过种植一季大麦,0—40cm土层含盐量从0.147％下降到0.117％,脱盐率达20.3％,60—100cm土层脱盐率达34.8％。经过方差分析,不同N素水平处理间的差异显著。试验结果表明,在自然肥力低的轻盐渍土上每亩施用纯N18斤左右为宜。采用盐分传感器的定点监测结果显示,在整个生育期内土壤溶液电导率低于大麦耐盐的极根值。本试验中大麦产量不高,可能主要不是盐分的抑制作用,而是因土壤肥力低和土壤结构不良所致。因此,在改良盐渍化土壤上种植基肥和秸桿还田等措施是极为重要的。江苏如东县棉花原种场自1982年海涂土地资源综合开发试点研究实施以来,在盐渍化土壤改良方面,通过完善水利配套、灌水洗盐、放养细绿萍和倒萍种稻等水改措施后,使含盐量在0.4％以上的盐渍化程度高的土壤中盐分较迅速下降。但受到河水水质较差的限制(早季河水矿化度2克/升以上),当土壤盐分下降到0.15—0.20％时,再继续采取水改措施盐分就难于再下降了。为此,我们根据本地区降水量丰沛的有利条件,回旱种植耐盐较强的大麦,观察旱作物复盖下的脱盐效果,并进行氮肥肥效试验作为合理施肥的根据。

Barley, a Rind of salt--tolerant crop, is adapted for gronwing salty soil,and in the meanwhile, Can bring about some effect on desalinization. Land,from which paddy rice had been raised for suceessive three years, cultivatedbarley for only one season, the salt content in 0--40cm layer soil droppedfrom 0.147% to 0.117 with a desalinization rate of 20.3%. In 60--100cm layersoil, the desalinazation rate went up to 34.8%. variat analysis of grain yieldsproved that their differances between nitrogen application treatments weresignificant. It also shrwed, adequated application rate in the low fertilty saltysoil fell on around 135kg N/ha. Dynamic conduetivitesi of soil solution testedby soil salintiy sensor in fixed monitor--spot were entirely lower then the ultimate limiting salt-tolerant value of barley through the whole growthperiod, The low yields of all treatments in this experiment were mainly due tothe low fertility and ill-fabrie of soil rather than the soil silt. Therefore,planting green mantire and plowing under soil ra are most essential measurements for improving silty soil.