不同轮作模式对黄淮平原潮土区土壤养分及作物产量的影响

通过大田试验,研究黄淮平原潮土区不同轮作方式对不同土层土壤速效养分和小麦产量构成因素及产量的影响。采用随机区组设置连续的小麦-玉米(WM-WM-WM)、1周期小麦-玉米+1周期小麦-大豆(WM-WS-WM)、1周期小麦-玉米+1周期小麦-夏花生(WM-WP-WM)、连续的小麦-夏花生(WP-WP-WP)和连续的小麦-大豆(WS-WS-WS)5个处理。结果表明,2017-2019年各处理土壤碱解氮、硝态氮、铵态氮、有效磷和速效钾含量在0-30 cm土层逐渐降低。随着栽培期限的增长,0-20 cm土层,WM-WP-WM和WP-WP-WP处理的土壤碱解氮(AN)含量最高。土壤硝态氮(NO₃^--N)和铵态氮(NH₄⁺-N)含量以WP-WP-WP和WS-WS-WS处理最优,而WP-WP-WP处理NO₃^--N和NH₄⁺-N含量最高,分别为43.98,17.58 mg/kg。WP-WP-WP处理有效磷(AP)含量和速效钾(AK)含量显著高于其他处理,分别为24.49,172.80 mg/kg。轮作模式和土层深度对NO₃^--N、NH₄⁺-N、AN、AP和AK有明显交互效应。WP-WP-WP处理小麦籽粒蛋白质在年际间变化明显,最高达到17.83%。小麦成熟期生物量和产量均以WP-WP-WP和WS-WS-WS处理最高。小麦氮收获指数与收获指数呈正相关关系。WP-WP-WP处理提高小麦的穗粒数(34.2个/穗),WS-WS-WS处理提高小麦亩穗数(26.7万穗/hm²)。总体来说,3年周期内,WP-WP-WP处理可以显著提高土壤碱解氮、硝态氮、铵态氮、有效磷以及地上部生物量和籽粒蛋白质含量。WS-WS-WS处理显著提高土壤铵态氮含量;WS-WS-WS和WP-WP-WP处理的小麦产量最高。因此,小麦-花生和小麦-大豆轮作模式均明显增加土壤有效氮含量,同时增加或维持小麦产量,推荐为该地区适宜的轮作模式。

Effect of Different Crop Rotations on Soil Nutrients and Crop Yield in Fluvo-aquic Soil in Huang Huai Plain

This study was aimed to select suitable crop rotation system by exploring the effect of the different crop rotation systems on soil available nutrients and wheat yield in Fluvo-aquic soil in Huang-Huai Plain. A field experiment was conducted with five treatments:(1) continuous annual wheat-maize (WM-WM-WM), (2) annual wheat-maize+annual wheat-soybean alternately (WM-WS-WM), (3) annual wheat- maize+annual wheat-peanut (WM-WP-WM), (4) continuous annual wheat-peanut (WP-WP-WP), (5) continuous annual wheat-soybean (WS-WS-WS). The results showed soil available nutrients decreased generally with soil depth under all treatments. The different of alkali-hydrolyzed nitrogen (AN) content in different soil layers was higher with time among treatments. The AN contents in 0-20 cm soil layer under WM-WP-WM and WP-WP-WP were higher. The nitrate nitrogen (NO₃^--N) and ammonium nitrogen (NH₄⁺-N) contents in 0-20 cm under WP-WP-WP and WS-WS-WS were higher, and with the highest as 43.98 mg/kg and 17.58 mg/kg under WP-WP-WP. The available phosphorus (AP) content and available potassium content under WP-WP-WP were higher, with the highest value as 24.49 mg/kg and 172.80 mg/kg, respectively. Both crop rotation system and soil depth affected NO₃^--N, NH₄⁺-N, AN, AP and AK. The grain protein content of wheat under WP-WP-WP changed significantly with time, with the highest value as 17.83%. The highest wheat biomass and yield were found under WP-WP-WP and WS-WS-WS. Moreover, there was a positive correlation between wheat N harvest index and wheat harvest index. The WP-WP-WP treatment increased the number of grains (34.2/ear), and the WS-WS-WS treatment increased the number of wheat (267 000 ears/hm²). During the experimental period, in the Fluvo-aquic soil in Huang-Huai Plain, the contents of soil AN, NO₃^--N, NH₄⁺-N, AP, above ground biomass and grain protein were increased under WP-WP-WP. The NH₄⁺-N content was increased under WS-WS-WS. Meanwhile, the highest wheat yield was obtained under WS-WS-WS and WP-WP-WP. Therefore, the wheat-peanut and wheat-soybean rotation models were suggested as the optimum crop rotation system in this area.