采用田间试验,研究了不同种植模式下茬口对小麦季土壤肥力的影响。研究表明,豆茬在土壤养分、酶活性方面优于苕茬,但不同的间套作条件下土壤肥力存在差异:(1)有机质表现为豆茬〉苕茬,成熟期苕茬以三熟﹥四熟,豆茬以净作〉套作;速效磷以豆茬持续降低,苕茬先降低再增加,成熟期以苕茬〉豆茬,苕茬又以三熟〉四熟,豆茬以麦/高/豆含量最高,达184.97 mg/kg。碱解氮、速效钾、全钾在小麦生长的旺盛季则始终表现为豆茬〉苕茬。(2)土壤酶茬口效应一致,同一茬口间的差异受种植模式的影响较大,成熟期磷酸酶和蔗糖酶活性表现为豆茬〉苕茬,苕茬以三熟〉四熟,豆茬磷酸酶活性则以麦/高/豆﹥麦/玉/豆﹥麦-豆,蔗糖酶活性则相反。
Based on the field experiment,this paper studied the effects of stubble on soil nutrient status,soil enzyme under different pianting systems.The results showed that compared with sweet potato stubble,soybean stubble contributed more to the soil nutrient and soil enzyme,because of the different intercropping,the soil fertility was different as following:(1)Soybean stubble were higher than sweet potato stubble in organic matter.At maturing stage sweet potato stubble with triple cropping﹥four cropping,soybean stubble with sole cropping﹥relay;Rapidly-available phosphorus with soybean stubble steadily reduced and sweet potato stubble firstly decreased then increased.At maturing stage sweet potato stubble was higher than soybean stubble,and sweet potato stubble with the order triple cropping,four cropping,the content of wheat/sorghum/soybean reached up to 184.97 mg/kg.In wheat growth of exuberant season soybean stubble was superior to sweet potato stubble in available N,K,total potassium.(2)The stubble effect of the soil enzyme was consistent,but the differences between the same stubbles were influenced by planting systems.At maturing stage soybean stubble were higher than sweet potato stubble in phosphatase and sucrase,further,sweet potato stubble with triple croping ﹥four,phosphatase of soybean stubble increased as the order wheat/sorghum/soybean,wheat/corn/soybean,wheat-soybean,yet the sucrase was opposite.