在宁南旱区将10 a生退化苜蓿草地翻耕后,进行了为期3年(2003-2005年)的草粮轮作试验,轮作作物为春小麦、马铃薯和谷子,以保持生长的退化苜蓿为对照,形成了27种不同草粮轮作方式。研究不同轮作处理对土壤水分的恢复状况以及产量效益,并通过综合指标法比较出最佳的草粮轮作模式。试验结果表明,退化苜蓿翻耕后3 a轮作期间,0~200 cm土壤水分均有不同程度恢复,而且主要受当年轮作作物影响较大;马铃薯为草粮轮作首选作物;不同轮作方式的作物总产量、经济总产值、水分利用效率和降水生产效率,以及第3 a 0~200 cm土壤水分含量等指标间差异显著(P〈0.05),马铃薯-马铃薯-马铃薯(PPP)、马铃薯-马铃薯-春小麦(PPW)、马铃薯-春小麦-马铃薯(PWP)和马铃薯-谷子-春小麦(PMW)为较好的轮作方式,其中马铃薯-马铃薯-春小麦(PPW)为综合指标法比较下的最佳轮作模式,该模式的作物总产量、总产值、水分利用效率、降水生产效率和0~200 cm土壤含水量分别为5 214.50 kg/hm2、15 301.87元/hm2、9.38kg/(hm2.mm)6、.87 kg/(hm2.mm)和254.58 mm,土壤水分净恢复量50.69 mm,可作为当地适宜的草粮轮作模式加以推广。
Experiments were carried out in the drought areas of southern Ningxia on the loess plateau during from 2003 to 2005,in which three kinds of crops including spring wheat,potato and millet were formed 27 kinds of different alfalfa-crop rotation patterns and rotated on the 10-year-old degraded alfalfa grassland,compared with continuous growing alfalfa.The purposes are to study and compare the soil moisture restoration conditions and crop production effectiveness between different rotations,then to explore more reasonable alfalfa rotation patterns by comprehensive index method.The results showed that,during 3-year crops rotation after alfalfa farmland was furrowed,soil moisture of alfalfa farmland in 0-200 cm depth layer has been restored in some degree and mainly influenced by the growing crop.Potato is the preferred rotation crop of three.Soil water content in 0-200 cm depth,total crops yields,total economic value,water use efficiency(WUE) and precipitation productive efficiency(PPE) of all rotation patterns have significantly differences(P0.05),respectively.Four of 27 kinds alfalfa-crop rotation patterns such as potato-potato-potato(PPP),potato-potato-spring wheat(PPW),potato-spring wheat-potato(PWP) and potato-millt-spring wheat(PMW) are better than the other patterns,and Potato-potato-spring wheat(PPW) is the optimal rotation pattern,which crops total yields,economic total value,WUE,PPE and soil water content in 0-200 cm depth is respectively 5 214.50 kg/hm2,1 5301.87 yuan RMB/ hm2,9.38 kg/(hm2 ·mm),6.87 kg/(hm2 ·mm) and 254.58 mm,and soil water net restoration content is 50.69 mm.So PPW pattern may be regarded as better feasible alfalfa-crop rotation pattern to popularize.