黄土丘陵沟壑区旱作农业轮作模式综合评价

目的]以不同轮作模式为研究对象,研究不同轮作模式对土壤容重、土壤含水量及作物产量的影响,优化兰州市旱地区作物种植制度。方法]以马铃薯(P)、玉米(M)、蚕豆(B)为供试作物,开展9种年际间轮作模式试验,分别为:(P-P-P),(M-M-M),(B-B-B),(P-M-P),(P-B-P),(M-P-M),(M-B-P),(B-B-P),(M-M-B)。测定不同轮作模式下,土壤容重、土壤水分及作物产量,并进行经济效益分析。结果]马铃薯轮作模式(P-M-P,P-B-P,M-P-M,M-B-P及B-B-P)能显著减少0—40cm土层的土壤容重,对40—60cm土层的土壤容重没有显著影响;不同作物轮作下土壤含水量、耗水量影响大小相似:玉米马铃薯蚕豆,水分利用效率受作物种类影响大小为:马铃薯玉米蚕豆,其中轮作模式以M-M-M下土壤含水量最低、耗水量最大,B-B-P下水分利用效率最高;同种作物轮作产量均高于连作产量,如2016年P-M-P,P-B-P,M-B-P,B-B-P较连作P-P-P产量分别提高了40.37%~79.28%,M-M-B蚕豆轮作较B-B-B连作增产23.56%,M-P-M轮作较M-M-M连作玉米产量提高10.51%;不同轮作模式经济收益大小与连作相比,轮作更利于产量与经济收益的提高。结论]综合土壤容重、水分利用效率、产量及经济效益,P-B-P与P-M-P轮作模式,能改善土壤环境、提高产量与经济效益可作为主推轮作模式。M-B-P轮作模式经济效益次之,但水分利用效益较高,能作为协调水分利用的种植模式。

Comprehensive Evaluation of Dryland Farming Rotation Systems in Loess Hilly and Gully Region

Objective] The objective of the study is to analyze the impact of different cropping systems on crop yield, soil bulk density and soil water content in Lanzhou City and to find the optimum cropping system in this area.Methods] The potato(P), maize(M) and faba bean(B) was selected as test crops under 9 annual rotation patterns (P-P-P, M-M-M, B-B-B, P-B-P, M-P-M, M-B-P, B-B-P, M-M-B). The soil bulk density, soil moisture, crop yield and economic benefits under different rotation patterns were analyzed.Results] P-M-P, P-B-P, M-P-M, M-B-P and B-B-P could significantly reduce soil bulk density in 0-40 cm soil layers, but had no significant effect on soil bulk density of 40-60 cm soil layers. The influence of rotation systems on soil water content was similar to that of water consumption, the order of the effects of crop types on soil water content, water consumption were maize > potato > faba bean, and WUE were potato > maize > faba bean, respectively. Under M-M-M treatment, the soil water content was the lowest, and water consumption was the highest, WUE of B-B-P treatment was the highest. The yield of rotation cropping was higher than that of continuous cropping. In 2016, compared with continuous cropping P-P-P treatment, the crop yield under P-M-P, P-B-P, M-B-P and B-B-P treatments increased by 40.37%~79.28%. Compared with continuous cropping B-B-B treatment, the crop yield under M-M-B treatment increased by 23.56%; Compared with continuous cropping M-M-M treatment, M-P-M treatment increased by 10.51%. Compared with continuous cropping, rotation cropping would more increase in crop yield and economic benefits.Conclusion] With respect to soil bulk density, WUE, crop yield and economic benefits, P-B-P and P-M-P were superior to the other seven rotation patterns, which could improve soil environment, and increase yield and economic benefits, and should be encouraged in Lanzhou City. The economic benefits under M-B-P was lower than P-B-P and P-M-P treatment, M-B-P had higher WUE, which could improve WUE.