不同种植模式对西南坡地水土保持及作物产值的影响

Effects of planting system on soil and water conservation and crop output value in a sloping land of Southwest China

通过3年定位监测试验研究了小麦/玉米/大豆全程免耕全程秸秆覆盖、小麦/玉米/大豆半程免耕半程秸秆覆盖、小麦/玉米/大豆全程翻耕不覆盖秸秆和小麦/玉米/甘薯全程翻耕不覆盖秸秆4种不同种植模式对西南坡地水土保持、土壤肥力及作物产值的影响.结果表明:在水土保持方面,小麦/玉米/大豆全程免耕全程秸秆覆盖模式的3年平均土壤侵蚀量和地表径流量最低,分别为1189kg.hm-2和215m3.hm-2,显著低于其他处理,比小麦/玉米/甘薯全程翻耕不覆盖秸秆模式分别低10.6%和84.7%.在土壤肥力方面,3种小麦/玉米/大豆模式都能增加土壤有机质、全氮、速效钾和碱解氮含量,以小麦/玉米/大豆全程免耕全程秸秆覆盖模式增加幅度最大,分别增加15.7%、18.2%、55.2%和25.9%,显著高于其他模式,小麦/玉米/大豆半程免耕半程秸秆覆盖模式次之,小麦/玉米/甘薯全程翻耕不覆盖秸秆模式最低.在作物产值方面,以小麦/玉米/大豆全程免耕全程秸秆覆盖模式的3年平均总产值和纯收入最高,分别为18809元.hm-2和12619元.hm-2,比其他几个处理分别增加2.2%～20.6%和3.8%～32.9%,总体效益最好.总之,小麦/玉米/大豆模式比传统的小麦/玉米/甘薯模式能更好地保持水土,减少土壤侵蚀量和地表径流量,增加土壤肥力和作物产值.

A three-year experiment was conducted to study the effects of wheat/maize/soybean with total no-tillage and mulching （NTM）,wheat/maize/soybean with part no-tillage and part mulching （PTM）,wheat/maize/soybean with total tillage without mulching （TWM）,and wheat/maize/sweet potato with total tillage without mulching （TWMS） on the soil and water conservation,soil fertility,and crop output value in a sloping land of Southwest China. The average soil erosion amount and surface runoff of NTM were significantly lower than those of the other three planting systems,being 1189 kg·hm-2 and 215 m3·hm-2,and 10.6% and 84.7% lower than those of TWMS,respectively. The soil organic matter,total N,available K and available N contents of NTM were increased by 15.7%,18.2%,55.2%,and 25.9%,respectively,being the highest among the test planting systems. PTM and TWM took the second place,and TWMS pattern had the least. NTM had the highest annual crop output value （18809 yuan·hm-2） and net income （12619 yuan·hm-2） in three years,being 2.2%-20.6% and 3.8%-32.9% higher than other three planting systems,respectively. In a word,the planting system wheat/maize/soybean was more beneficial to the water and soil conservation and the improvement of soil fertility and crop output value,compared with the traditional planting system wheat/maize/sweet potato.