深松对新疆膜下滴灌棉花根系特性及养分吸收的影响机制

Recently subsoiling is one of the most important researches in the field study. Subsoiling can effectively break the bottom of the plough, improve soil environment, and improve crop growth and yield. The root system is the main organ which absorbs soil moisture and nutrients from soil, and is the basis for crop growth and production. The improvement of soil environment is bound to affect crop root growth and nutrient uptake, When the applicant was studying the effects of the deep pine on the soil in the cotton field, it was found that the deep pine had an effect on the root system of the cotton, which would affect the growth and production of cotton, but how did the deep pine affect the growth of the cotton root system? It's not clear. Therefore, this project is to film with drip irrigation of cotton in xinjiang as the research object, by setting the soil column culture and field plot test, the study under the condition of different subsoiling， cotton root morphology, enzyme activity, hormone level changes of nutrient uptake and root system characteristics. Based on the method of root scanning, root drilling, image analysis and indoor enzyme activity, hormone level and nutrient testing, this paper analyzed the characteristics of cotton root system and nutrient index of cotton at different birth period, and clarified the influence mechanism and interrelation of deep pine on the root morphology, physiological activity and nutrient absorption of cotton in xinjiang film, and provided theoretical basis for the scientific application of deep pine in cotton field in xinjiang and the construction of cotton root system regulation technology.

深松是近年来耕作领域研究的主要热点之一，深松能够有效打破犁底层，改善土壤环境，促进作物生长及产量提高。根系是作物吸收土壤水分和养分的主要器官，是作物生长和产量形成基础。土壤环境的改善势必会影响作物根系生长和养分吸收，申请人前期在研究深松对棉田土壤性状影响时，发现深松对棉花根系生长产生影响，进而会影响棉花产量形成，但深松是如何影响棉花根系生长？尚不清楚。因此，本项目以新疆膜下滴灌棉花为研究对象，通过设置土柱栽培与田间小区试验，研究不同深度深松条件下，棉花根系形态、酶活性、激素水平及根系养分吸收变化特征。采用根系扫描、根钻法、图像分析与室内酶活性、激素水平及养分测试相结合的方法，通过对不同生育时期棉花根系特性及养分指标的测试分析，明确深松对新疆膜下滴灌棉花根系形态特性、生理活性、养分吸收的影响机制及其相互关系，为深松在新疆棉田科学应用及对棉花根系调控技术构建提供理论依据。

深松改善土壤环境，提高棉花产量，必然会引起棉花根系形态及酶活性的变化，开展深松对棉花根系形态特征、酶活性的影响及其与养分吸收间的作用关系的研究,结果显示：①深松提高了棉花主根长度，深松40cm主根相比CK提高了85.99%，棉花根系总长度显著增加25.92%，根长密度、根直径、根表面积、根尖数、分叉数表现最优，较CK提高7.89%、32.62%、28.29%、36.96%、40.68%。深松促进蕾期根系下扎，抑制了根系向水平方向扩展，深松40cm在0-60cm土层根长密度较CK提高5.05%-19.27%，而花铃期和吐絮期低于CK。②深松使根系MDA显著下降，蕾期2.25%-7.25%、花铃期0.47%-13.81%、吐絮期4.33%-9.41%，深松使GA含量增加0.87%-11.82%，IAA含量增加1.79%-12.85%，ABA含量减少1.78%-12.93%。深松40cm处理GA和IAA显著高于CK。③深松能平衡棉田土壤养分，减小土壤养分空间变异性。深松40cm在蕾期使深层速效氮增加，较CK降低29.28%，速效磷变化趋势一致，而速效钾则相反。花铃期，深松使20-60cm速效氮增加，水平方向速效磷逐渐减小，而20-40cm速效钾增加。吐絮期，深松40cm处理0-40cm速效钾较CK增加24.46%-36.7%。④深松提高了蕾期20-40cm根系氮素，而0-60cm根系磷素增加6.82%-28.41%，0-20cm根系钾素提高；花铃期深松40cm、50cm处理0-40cm根系氮素下降21.31%-29.11%，磷素下降1.15%-11.19%，但深松40cm根系钾素在0-60cm下降6.44%-18.64%。吐絮期20-40cm深松40cm、深松50cm根系氮素下降16.2%-19.9%，根系磷素20-40cm提高19.00%-22.14%，其余土层下降7.44%-13.11%。根系钾素在0-40cm无显著差异，40-60cm下降7.44%-8.63%。深松使蕾期植株氮素增加17.37%-26.57%，吐絮期增加33.63%-59.41%；深松40cm植株磷素较CK提高56.18%；而植株钾素在花铃期、吐絮期与深松深度呈正相关，表明深松对植株中后期钾素的积累有促进作用。研究结果为制定合理的深松调控技术和棉花增产机理提供理论依据和生产实践指导。