张金珠, 王振华, 虎胆·吐马尔白. 秸秆覆盖对滴灌棉花土壤水盐运移及根系分布的影响[J]. 中国生态农业学报(中英文), 2013, 21(12): 1467-1476. DOI: 10.3724/SP.J.1011.2013.30621
引用本文: 张金珠, 王振华, 虎胆·吐马尔白. 秸秆覆盖对滴灌棉花土壤水盐运移及根系分布的影响[J]. 中国生态农业学报(中英文), 2013, 21(12): 1467-1476. DOI: 10.3724/SP.J.1011.2013.30621
ZHANG Jin-Zhu, WANG Zhen-Hua, Hudan·TUMAREBI. Influence of straw mulching on soil water/salt movement and cotton root distribution under drip irrigation[J]. Chinese Journal of Eco-Agriculture, 2013, 21(12): 1467-1476. DOI: 10.3724/SP.J.1011.2013.30621
Citation: ZHANG Jin-Zhu, WANG Zhen-Hua, Hudan·TUMAREBI. Influence of straw mulching on soil water/salt movement and cotton root distribution under drip irrigation[J]. Chinese Journal of Eco-Agriculture, 2013, 21(12): 1467-1476. DOI: 10.3724/SP.J.1011.2013.30621

秸秆覆盖对滴灌棉花土壤水盐运移及根系分布的影响

Influence of straw mulching on soil water/salt movement and cotton root distribution under drip irrigation

  • 摘要: 干旱区棉田残膜污染日益严重, 秸秆覆盖能从根本上杜绝农田残膜增量。为探索秸秆覆盖代替塑料薄膜与滴灌结合的可行性, 需了解秸秆覆盖对滴灌棉田土壤水盐分布及棉花根系的影响特点, 同时探索耕作层以下30 cm处埋设一层秸秆进行深层秸秆覆盖与滴灌结合的效果。本文采用测坑试验研究了3种秸秆覆盖方式(表层覆盖、30 cm深层覆盖和无覆盖)与滴灌结合在2种土壤条件下(非盐碱土和盐碱土), 棉花根系分布稳定后的絮期土壤水盐运移及棉花根系分布特征。结果表明: 表层覆盖对于土壤整体保水性较好, 能有效抑制耕层水分散失和盐分聚集; 30 cm深层覆盖整体保水性优于无覆盖, 相对表层覆盖仅在秸秆层以下靠近滴灌带的有限范围内具有优势, 并显著提高耕层以下土壤水分含量, 但在棉花絮期对于盐分抑制作用不明显。秸秆覆盖通过对水盐运动的影响而显著影响棉花根系分布, 尤其对深层根系分布影响更大。非盐碱土条件下, 0~28 cm土层, 无覆盖处理根长密度、根重密度、根长密度比重均最大, 表层覆盖根长密度最小, 但根重比重最大, 30 cm深层覆盖根重密度最小; 在28~70 cm土层, 30 cm深层覆盖根长密度最大, 表层覆盖根长密度最小, 但根长密度比重最大, 无覆盖根长密度比重最小, 其中在28~56 cm土层30 cm深层覆盖根重密度和根重比重均最大。盐碱土条件下, 0~28 cm土层, 表层覆盖与30 cm深层覆盖根长密度和根长比重均高于无覆盖处理, 同时表层覆盖根重密度最高, 30 cm深层覆盖根重密度和根重比重均最低; 在28~70 cm土层情况相反, 30 cm深层覆盖处理根重比重最大, 但根重密度最小。说明表层覆盖可促进非盐碱土及盐碱土耕作层根系发育, 30 cm深层覆盖限制上层根系发育, 但促进30 cm以下土层根系发育, 在盐碱逆境下秸秆覆盖可促进根系向更细更长方面发育。秸秆覆盖与滴灌结合在干旱区具有良好应用前景。

     

    Abstract: With wide application of plastic mulching in cotton fields in the arid regions of China, residual plastic films have become a growing concern. Compared with plastic mulching, straw mulching has been noted to safely avoid the residual problem associated with plastic mulching. To explore the feasibility of replacing plastic mulching with straw mulching in a combined mulching and drip irrigation system, the effects of straw mulching on distributions of soil water and salt and cotton root system in drip-irrigated cotton fields were evaluated in this study. In addition, the effect of deep straw mulching (buried a layer of straw at 30 cm soil depth) coupled with drip irrigation was evaluated. Pit test experiments were carried out on two soil types (non-saline and saline-alkali soils) with three straw mulching treatments - surface mulching, deep mulching and non-mulching - coupled with drip irrigation. Samples were taken at cotton batt stage when the distribution of root systems was stable, followed by analyses of water, salt and root distribution characteristics. The results showed that surface mulching was fairly effective in soil moisture conservation and effectively prevented water loss via evaporation and salt accumulation in the plough layer. Deep mulching was generally better in effect regarding water conservation than non-mulching. Deep mulching was only advantageous over surface mulching in soil areas near irrigation lines under the straw layer. While deep mulching significantly improved soil moisture content below the plough layer, it had no apparently effect on salt at the cotton batt stage. Straw mulching significantly influenced the distribution of cotton root systems, especially in deep soil layers, by controlling the movements of water and salt. For non-saline soils, in the 0 28 cm soil layer, the highest root length density, root weight density and root length density proportion occurred under non-mulching. Although surface mulching had the smallest root length density, it also had the largest proportion of root weight density. Moreover, the lowest root weight density was under deep mulching. Deep mulching had the highest root length density in the 28 70 cm soil layer. Surface mulching had the smallest root length density but the largest root length density proportion. Then non-mulching had the lowest root length density proportion. In the 28 56 cm soil layer, deep mulching had both the highest root weight density and root weight density proportion. For saline-alkaline soil, in the 0 28 cm soil layer, both surface and deep mulching treatments had higher root length density and root length density proportion than non-mulching. Then surface mulching had the highest root weight density. The lowest root weight density and root weight density proportion occurred under deep mulching. On the contrary, deep mulching had the highest root weight density proportion and the lowest root weight density in the 28 70 cm soil layer. These findings suggested that surface mulching promoted root development in the plough layers of both saline-alkaline and non-saline soils. Deep mulching inhibited root system development in the upper soil layers but enhanced root system development in soil layers below the 30 cm soil depth. Also straw mulching caused the root system to be thinner and longer under unfavorable salt and alkali conditions. Therefore the combination of straw mulching and drip irrigation was highly promising for efficient cotton production in arid areas.

     

/

返回文章
返回