苗带深松条件下秸秆覆盖对春玉米土壤水温及产量的影响

Effect of Straw Mulching on Soil Temperature, Soil Moisture and Spring Maize Yield under Seedling Strip Subsoiling

免耕秸秆覆盖是中国北方干旱半干旱区一种重要的保护性耕作模式。为明确宽行覆盖窄行深松交错种植条件下覆盖带适宜的秸秆覆盖量和覆盖方式,2012—2013年在河北省廊坊市进行了春玉米的田间试验。选用郑单958为试验材料,采用80 cm＋40 cm宽窄行种植,宽行间覆盖秸秆,窄行间进行苗带深松,设置8.42 t hm–2覆盖量下粉碎覆盖（100SC）、整秆覆盖（100SP）、4.21 t hm–2覆盖量下粉碎覆盖（50SC）、整秆覆盖（50SP）和不覆盖（CK）处理,测定土壤水分和温度、出苗状况、物质积累、产量及产量构成。结果表明,秸秆覆盖与深松结合条件下,4种覆盖处理与对照相比均提高了土壤含水量,其中50SC处理在花前0~15 cm土壤降温幅度最小,其他覆盖处理显著降低花前土壤温度。各覆盖处理明显提高了苗期整齐度,秸秆覆盖对苗期的生育期天数略有推迟。与CK相比,50SC提高了春玉米地上部生物量,促进花后干物质积累,千粒重和穗粒重分别提高10.9%（P〈0.05）和6.5%（P〈0.05）,产量提高4.78%,达12243 kg hm–2。50SC条件下产量与全生育期干物质积累（DMA）、花后/花前DMA呈极显著正相关。说明宽行覆盖窄行深松交错种植有利于缓和秸秆覆盖对出苗的物理阻碍,其中秸秆以4.21 t hm–2的覆盖量粉碎覆盖效果最好,该处理可为玉米提供稳定有利的土壤水分和温度条件,提高了生育后期的物质积累以及籽粒产量。

No-tillage with straw mulching is widely adopted in arid and semi-arid regions of North China which effectively pre-serves the water content. But it decreases the soil temperature and results in seed germination delaying. We developed a new way of no-tillage with straw mulching. The straw mulching was conducted only in the wide inter-row, and subsoiling was conducted in the narrow inter-row. To determine the quantity and method of straw mulching in this new no-tillage way, we conducted field ex-periments in 2012 and 2013 in Langfang, Hebei province. The maize cultivar Zhengdan 958 was planted with 80 cm＋40 cm in-ter-row planting spacing. The treatments of wide inter-row included mulching with 8.42 t ha-1 of chopped straw （100SC） and prostrated straw （100SP）, 4.21 t ha-1 of chopped straw （50SC） and prostrated straw （50SP）, with no straw mulching as CK. Soil temperature, soil moisture, emergence quality, days of growth period, dry matter accumulation, yield and its components were compared among these treatments. The results showed that the soil moisture were increased in all the four straw mulching treat-ments. The 50SC treatment had the least influence on decreasing soil temperature compared with CK. The emergence uniformity of all straw mulching treatments increased significantly. Straw mulching had less significant effects on duration from sowing to seedling. Above-ground biomass of 50SC was improved, and its dry matter accumulation was promoted at post-anthesis stage. Compared with CK, the yield of 50SC was increased by 4.78%, and 1000-kernel weight and kernel weight per ear by 10.9%and 6.5%, respectively. The yield of 50SC had very significant correlation with its whole period dry matter accumulation （DMA） and ratio of post-anthesis to pre-anthesis DMA. Therefore, the mulching technique in this study has less physical constraint to emer-gence, and in this new way of straw mulching 4.21 t ha-1 of chopped straw mulching is better for maize. With this condition, the adverse effects of straw on emergence are alleviated and dry matter accumulation in later period and yield of maize are increased.