苏丹草-黑麦草轮作制中施肥对饲草产量与土壤酶的影响

 【目的】为苏丹草-黑麦草这一新型种植制度的科学施肥、土壤肥力的改善提供依据。【方法】采用4年苏丹草(Sorghum sudanense)与黑麦草(Lolium L.)轮作定位试验研究氮、磷、钾肥对饲草产量、土壤蔗糖酶、脲酶和磷酸酶的影响。【结果】氮、磷、钾肥配施(NPK处理)明显增加苏丹草、黑麦草鲜草产量,4个年度的饲草总产量在各个处理中均最高,分别比NP(氮、磷肥配施)处理增产17.9%、17.3%、21.7%、23.2%,分别比NK(氮、钾肥配施)处理增产26.9%、20.2%、23.3%、25.9%,分别比PK(磷、钾肥配施)处理增产312..9%、339.8%、231.7%、223.1%,且效果显著。苏丹草-黑麦草轮作制中,NPK处理的土壤蔗糖酶、脲酶高于CK、PK处理,部分达到显著水平,与NP、NK处理相当;土壤磷酸酶以碱性磷酸酶为主,苏丹草、黑麦草试验期NP、NK、NPK处理的碱性磷酸酶均显著低于CK、PK处理。【结论】苏丹草-黑麦草轮作制中,氮、磷、钾肥配施能够明显提高饲草产量,影响土壤蔗糖酶、脲酶、磷酸酶活性,从而改善土壤肥力。

Effect of Fertilization on Forage Yield and Soil Enzymes Under Sudangrass and Ryegrass Rotation Regime

【Objective】 The sudangrass and ryegrass rotation is a new type of cropping system in the south of China, and it develops very fast in recent years. Guidelines for proper fertilization are needed for improvement of soil fertility in this rotation. 【Method】 The effects of NPK fertilizers on forage yield, sucrase, urease and phosphatase in soil under sudangrass and ryegrass rotation regime were studied based on the four-year fixed location field experiments. 【Result】 The results indicated that the NPK combination significantly increased the fresh yield of sudangrass and ryegrass. The total yield in NPK treatment was the highest among all treatments from 2005 to 2009, and was 17.9%, 17.3%, 21.7%, and 23.2% higher than that of NP treatment, 26.9%, 20.2%, 23.3%, and 25.9% higher than that of NK treatment, and 312.9%, 339.8%, 231.7%, and 223.1% higher than that of PK treatment, respectively. In the rotation, the activities of soil sucrase and urease in NPK treatment were higher than that in CK and PK treatments, while were similar to that of NP and NK treatments. For soil phosphatase, alkaline phosphatase activity was higher than acid phosphatase activity in the rotation, and NP, NK and NPK treatments were lower than CK and PK treatments. 【Conclusion】 The combination of N, P and K fertilizers could increase yield of forage, influence the activities of sucrase, urease and phosphatase in soil and improve soil fertility in the sudangrass and ryegrass rotation system.