秸秆覆盖还田及腐解率对土壤温湿度与玉米产量的影响

Effects of Straw Mulching and Decomposition Rate on Soil Temperature and Humidity and Maize Yield

摘要:

为探究东北黑土区秸秆覆盖还田及其腐解率对土壤温湿度和玉米产量的影响，2019年和2020年在大庆市肇州县进行了秸秆覆盖全量还田（试验组）和留茬10cm左右还田处理（对照组）对比试验。结果表明：试验组秸秆腐解率4月仅为4.3%和4.5%，5月为17.8%和16.8%，6月为22.3%和27.8%，秸秆腐解主要集中在7、8月。土壤温湿度受地表残余秸秆影响较为明显，5月试验组土壤含水率比对照组分别低1.2、1.1个百分点，但随着秸秆腐解率增大，试验组土壤含水率在6—9月平均高出对照组约3个百分点。试验组0cm处土壤温度在5—8月日间大气升温阶段受到抑制，相同时段温度与对照组最大差值为4.8、3.8℃，10、20cm处土壤温度在5、6月受地表秸秆覆盖影响较为明显，7—9月影响不显著，30cm处土壤温度除6月影响明显外，其他月份相比对照组变化较小。在每天大气降温时段，试验组不同深度处的土壤温度降温较对照组平缓，保温保墒作用较明显。地表秸秆覆盖影响作物出苗，试验组比对照组出苗分别晚4、3d，在拔节期对照组比试验组的作物株高分别高7.3、7.4cm，茎粗大0.2、0.1cm，但在抽穗期和灌浆期试验组的株高和茎粗均大于对照组；2019年试验组的玉米产量为10716.0kg/hm2，比对照组增产193.5kg/hm2。综合分析，秸秆覆盖还田对土壤温湿度具有双向阻碍作用，秸秆腐解程度对双向阻碍作用有一定影响，秸秆覆盖全量还田的保温保墒作用促进了玉米的生长和产量提升。

Abstract:

In order to explore the effects of straw mulching and decomposition rate on soil temperature, humidity, and maize yield in northeast black soil region, comparative experiments were conducted between total straw mulching (experimental group) and leave stubble treatment of about 10cm straw mulching (compared group) in Zhaozhou County of Daqing City in 2019 and 2020. The results showed that the decomposition rate of straw of the experimental group was only 4.3% and 4.5% in April, 17.8% and 16.8% in May, 22.3% and 27.8% in June, and the decomposition of straw was mainly concentrated in July to August. The soil temperature and humidity were significantly affected by residual straw on the ground, and the soil moisture content of the experimental group was 1.2 percentage points and 1.1 percentage points lower than that of the compared group in May. However, with the increase of straw decomposition rate, the average soil moisture content of the experimental group was about 3 percentage points higher than that in the compared group from June to September. From May to August, the soil temperature at 0cm was restrained during diurnal warming phase, and the maximum difference between experimental group and compared group respectively was 4.8℃ and 3.8℃ in the same period. The soil temperature at 10cm and 20cm was evidently affected by the straw mulching in May and June, and was not significant from July to September. Compared with the compared group, the effect of soil temperature at 30cm was significantly affected in June, but it was changed little in other months. During the daily cooling period, the soil temperature at different depths in the experimental group was decreased more gently than that in the compared group, and the effect of soil temperature preservation and soil moisture preservation was obvious. The straw mulching affected the crop emergence, the crop emergence of the experimental group affected by straw mulching was 4d and 3d later than that of the experimental group. At jointing stage, the plant height of the compared group was 7.3cm and 7.4cm higher than that of the experimental group, and the stem diameter was 0.2cm and 0.1cm thicker than that of the experimental group, respectively. However, the plant height and stem diameter of the experimental group were higher than those of the compared group at other stage. The maize yield of the experimental group was 10716.0 kg/hm2 in 2019, which was 193.5kg/hm2 higher than that of the compared group. In conclusion, the straw returned by crushing and mulching had a two-way hindrance effect on soil temperature and humidity, and the degree of straw decomposition had a certain impact on the two-way hindrance effect. The effect of straw mulching on heat preservation and soil moisture preservation promoted the growth and yield of corn.