有机培肥与轮耕方式对夏玉米田土壤碳氮和产量的影响

探明不同轮耕和有机培肥方式对夏玉米田土壤碳氮及其酶活性的影响,对提升农田土壤肥力及促进玉米高产具有重要意义。设秸秆(P)与牛粪(F)两种有机培肥方式和小麦季旋耕-玉米季深松(RS)、小麦季深松-玉米季免耕(SN)、小麦季翻耕-玉米季免耕(CN) 3种轮耕方式,共6个处理,于2015—2016和2016—2017玉米收获期采样测定,研究了不同有机培肥和轮耕方式对土壤碳氮及其酶活性和作物产量的影响。结果表明,轮耕方式、有机肥及其交互效应对土壤肥力有显著影响。在0～10 cm和10～20 cm土层,与轮耕方式CN相比, RS和SN能够显著提高土壤有机碳、全氮含量和脲酶、蔗糖酶活性。在轮耕方式RS中,与施用牛粪相比,秸秆还田显著提高了10～20 cm、20～30 cm和30～40 cm土层的有机碳含量,增加了10～20 cm土层的全氮含量和蔗糖酶活性。在轮耕方式SN中,与秸秆还田相比,施用牛粪显著提高了0～10 cm和10～20 cm土层的有机碳、全氮含量和蔗糖酶活性,增加了各土层脲酶活性。与秸秆还田+翻耕-免耕(PCN)相比,秸秆还田+旋耕-深松(PRS)和施用牛粪+深松-免耕(FSN)能显著提高土壤肥力。在0～10 cm和10～20 cm土层,各处理中以FSN增加土壤有机碳、全氮含量和蔗糖酶、脲酶活性最为明显。轮耕方式、有机肥及其交互效应对产量有显著影响。轮耕方式RS和SN的产量较CN分别显著提高了1.89%～10.49%、5.44%～11.99%。在轮耕方式RS中,产量表现为秸秆还田较施用牛粪显著提高了2.91%～3.11%;而在轮耕方式SN中,则表现为秸秆还田较施用牛粪显著降低了5.02%～9.07%。两年玉米产量均表现为FSNPRSFRSPSNFCNPCN。综上所述,在6种处理中,处理FSN在提高土壤肥力和产量方面最为显著,可以作为试验及周边地区适宜的轮耕培肥方式。

Effect of organic fertilizer and rotational tillage practices on soil carbon and nitrogen and maize yield in wheat-maize cropping system

Quantitatively analyzing the effects of different tillage rotations and organic fertilization practices on soil carbon, nitrogen and their enzyme activities is of great importance to improve soil fertility and promote maize yield. This study was intended to explore changes of soil organic carbon, total nitrogen, urease and sucrase activities under different tillage rotations and organic manure patterns in wheat-maize cropping system of North China Plain. Six treatments were compared, which were straw returning with rotary tillage-subsoiling (PRS), straw returning with subsoiling-no tillage (PSN), straw returning with conventional tillage-no tillage (PCN), cow manure with rotary tillage-subsoiling (FRS), cow manure with subsoiling-no tillage (FSN), and cow manure with conventional tillage-no tillage (FCN). The tillage mode, organic manure and their interactions had significant effects on soil fertility. The RS and SN patterns had higher contents of soil organic carbon and total nitrogen, and higher enzyme activities of urease and sucrase in 0-10 cm and 10-20 cm soil layers compared with the CN pattern. In rotation tillage mode of RS, straw returning significantly increased the soil organic carbon contents in 10-20 cm, 20-30 cm, and 30-40 cm soil layers, and increased the total nitrogen content and sucrase activity in 10-20 cm soil layer. In rotation tillage mode of SN, the soil organic carbon, total nitrogen content, and sucrase activity in 0-10 cm and 10-20 cm soil layers, and urease enzyme activity in each soil layer, were significantly increased by applying cow manure compared with straw returning. Compared with PCN, PRS and FSN could significantly increase the soil fertility. The soil organic carbon, total nitrogen, urease and sucrase activities in FSN treatment were the highest in 0-10 cm and 10-20 cm soil layers in all treatments. The tillage mode, organic manure and their interactions had significant effects on maize yield. Compare with CN pattern, maize yield of the RS and SN patterns were averagely increased by 1.89%-10.49% and 5.44%-11.99%, respectively. In rotation tillage mode of RS, the yield under straw returning was significantly increased by 2.91%-3.11% compared with that under using cow manure; while in rotation tillage mode of SN, the yield under straw returning was 5.02%-9.07% lower than that under applying cow manure. The average yields of two years were in the order of FSN>PRS>FRS>PSN>FCN>PCN. This study demonstrates that cow manure with subsoiling-no tillage can increase the soil organic carbon, total nitrogen, and urease and sucrase activities, and increase the crop yield as a result. Thus, cow manure with subsoiling-no tillage management practice is a better mode for increasing soil fertility and crop productivity, which should be expected to be adopted in the North China Plain.