【作者】 张丽；

【导师】 王璞； 陶洪斌；

【作者基本信息】 中国农业大学 ， 作物栽培学与耕作学， 2014， 博士

【摘要】 我国干旱半干旱地区,水资源严重匮乏,干旱频繁发生。耕作制度上,由于现有传统的浅旋耕耕作及近20多年小型农机具在田间反复操作,使得耕地形成坚实的犁底层,土壤结构紧实、物理性状变劣。施肥制度上,长期单一施用化肥,土壤供肥能力和保水性能差。犁底层的存在和养分胁迫是制约降雨高效利用的主要因素。为了增加农田土壤蓄水保墒能力,本文研究了深松结合秸秆还田耕作技术和深松结合有机肥措施对晋中北部地区两种主要类型土壤(粘土和壤土)的物理化特性和土壤水分保蓄能力的影响以及玉米生长的响应,旨在为土壤的扩蓄增容和早地农业的可持续发展提供理论和实践依据。研究结果如下：1深松和培肥对农田土壤理化特性的影响深松可以打破土壤犁底层,显著降低粘土和壤土10-30cm土层范围内的土壤容重；调节土壤孔隙度,增加粘土10～30cm土层范围内的土壤总孔隙度、毛管孔隙度和非毛管孔隙度,增加壤土10-30cm土层范围内的土壤总孔隙度、毛管孔隙度和20-30cm土层土壤非毛管孔隙度；改善粘土和壤土20-30cm土层土壤固、液、气三相状况；深松结合连年秸秆还田进一步优化了壤土耕层环境,同时显著降低玉米拔节期土壤地表结皮的厚度和紧实度,缓解了土壤板结状况,增加了降雨入渗。深松结合秸秆还田和深松及农家肥均不同程度的增加了0-30cm土层范围内的土壤有机质、全氮、速效磷和速效钾含量。2深松和培肥对农田土壤水分含量的影响壤土上,深松结合秸秆还田和深松均增加了播前0～120cm土层范围内的土壤含水量；深松和秸秆还田均显著提高了玉米拔节期和大喇叭口期0～60cm土层土壤含水量；秸秆还田也显著提高了玉米抽雄吐丝期和灌浆中期0～60cm土层和成熟期0-200cm土层土壤含水量,而深松处理效果均不明显。粘土上,深松增加了播前0-200cm土层范围内的土壤含水量,但显著降低了20-30cm土层土壤含水量；深松对玉米拔节期0～60cm土层土壤含水量影响显著,农家肥及其互作效应均不明显；深松和不同用量农家肥处理均对玉米大喇叭口期0～60cm土层土壤含水量均无显著影响,但其互作效应显著,以深松结合中量和高量农家肥处理效果最好；深松和不同用量农家肥处理及互作效应均对玉米抽雄吐丝期0～60cm层土壤含水量无显著影响；不同用量农家肥处理均显著增加了玉米灌浆中期0～60cm土层土壤含水量,但深松及互作效应不明显；深松和不同施用量农家肥处理均显著增加了玉米成熟期0～200cm土层土壤含水量,但其互作效应不明显。3深松和培肥(?)玉米根系分布、形态特征和活力的影响深松结合秸秆还田和深松与旋耕处理相比,玉米根系在土壤0～20cm土层的分布相对减少,较多根系向下伸长生长,20cm土层以下根干重、根长密度、根表面积密度和根体积密度均大于旋耕处理。从整个土壤剖面看,深松结合秸秆还田处理下根干重密度、根表面积密度和根体积密度所占比例在40cm土层以下较深松处理有所提高,其原因可能是深松结合秸秆还田处理相对良好的肥水条件更进一步促进了玉米根系的下扎。深松结合秸秆还田、深松和农家肥也同时使玉米在抽雄吐丝期根系伤流量不同程度增加。因此,通过深松结合有机培肥可以构建合理的耕层结构,促进根系的固定和下扎,缓解根系生长空问的胁迫,使根系在土壤中合理分布,增加根系活力。4深松和培肥对玉米叶水分和光合效率的影响深松结合秸秆还田、深松和农家肥均提高了玉米在不同生育时期的叶水势、叶片相对含水量,并使玉米在生长后期叶片始终具有较高的SPAD值。说明深松结合秸秆还田、深松和农家肥处理可以较长时间地维持玉米叶片相对较高的SPAD值,即延长了叶片的功能期,延缓了叶片的衰老进程,有利于玉米高产的形成。深松结合秸秆还田处理明显的提高了玉米的光合速率、蒸腾速率和气孔导度；不同施用量农家肥处理也不同程度的增加了玉米在拔节期、抽雄吐丝期和灌浆中期的光合速率、蒸腾速率和气孔导度,而深松作用不明显,深松和农家肥的互作效果亦不明显。5深松和培肥对玉米生长发育、产量、品质和水分利用效率的影响深松结合秸秆还田和施用中、高量农家肥可显著提高玉米在大喇叭口期、抽雄吐丝期和灌浆中期的株高和茎粗,降低穗位与株高之比和叶片衰老指数。深松结合秸秆还田、深松处理和不同施用量农家肥处理显著提高了玉米成熟期籽粒蛋白质含量。深松结合秸秆还田和深松处理也显著增加了玉米籽粒产量。粘土上,深松对玉米籽粒产量影响显著,农家培肥对籽粒产量影响显著,但深松与农家肥的互作效应不显著。深松结合秸秆还田和深松处理均不同程度的提高了水分利用效率和降雨利用效率。粘土上,深松对水分利用效率和降雨利用效率影响均明显,农家肥对水分利用效率和降雨利用效率影响达极显著水平,但深松与农家肥的互作效应不明显。更多还原

【Abstract】 Water scarcity and droughts occur frequently in arid and semi-arid areas of China. Conventional plow and frequent operation of small machinery applied in this area have run more than20years, which led to strong hardpan, compaction soil layer, and poor soil physical property. Additionally, mineral fertilizers were commonly applied without straw or organic fertilizer returning to the soil. The soil nutrition and moisture preserving capability became weak. Therefore, field experiments were conducted in fluvo-aquic soil (clay) and cinnamon soil (loam) that were two major soil types in central and northern area of Shanxi province. The purpose of this research was to provide theoretical and practical basis for enhancing soil storage capacity and agricultural sustainable development of dryland. The main results were as follows:1Effects of sub-soiling and organic fertilizer application on soil physical and chemical characteristicsSub-soiling could break the plow layer and significantly reduced soil bulk density at10-30cm soil layer both in clay and loam soil. Sub-soiling also regulated soil porosity, including increasing soil total porosity, capillary porosity and non-capillary porosity at10-30cm soil layers in clay soil. Moreover, soil total porosity and capillary porosity at10-30cm soil layer, non-capillary porosity at20-30cm soil layer on loam soil were increased. Sub-soiling improved soil solid, liquid and gas phase conditions at20-30cm soil layer both on clay and loam. Sub-soiling with straw incorporated further optimized the farming environment, significantly reduced crust thickness and compaction of surface soil at the jointing stage of maize as well as alleviated soil hardening conditions of the farming ground and increased rainfall infiltration. Sub-soiling combinedwith straw incorporated, sub-soiling and organic fertilizer increased soil organic matter, total nitrogen, available phosphorus and available potassium content at0-30cm soil layer to different degrees.2Effects of sub-soiling and organic fertilizer application on soil moistureIn loam soil, the sub-soiling with straw incorporated and sub-soiling treatments increased soil moisture at0-120cm soil layer compared with the control treatment before sowing. The sub-soiling and straw crushing returning both significantly increased soil moisture over0-60cm soil layer at jointing and trumpeting stages of maize. The straw crushing returning significantly increased soil water moisture over0-60cm soil layer both at silking and milking stages of maize, but the sub-soiling is not so remarkable. The straw crushing returning also significantly increased soil moisture over0-200cm soil layer at maturity stage of maize, and the sub-soiling was notable as well.In clay soil, the sub-soiling treatment increased the soil moisture at0-200cm soil layer compared with the control treatment before sowing. But the soil moisture reduced remarkably by11.89%(p<0.05) at20～30cm soil layer under sub-soiling compared with the control. The reason might be that sub-soiling in spring could accelerate the loss of soil moisture of20-30cm soil layer. The sub-soiling significantly increased soil moisture over0-60cm soil layer at jointing stage of maize, but the different use levels of organic manure were not distinct and the interplay of those two elements were not as significant. The sub-soiling and the different use levels of organic manure were notable on soil moisture over0-60cm soil layer on trumpeting stage of maize, but the interplay of those two elements were significant. Among them, sub-soiling with medium and high organic manure had the best effect. The sub-soiling and the different use levels of organic manure were not remarkable on soil moisture over0-60cm soil layer at silking stage of maize, and the interplay of those two elements were not as significant too. The cause might be the high rainfall of this period so that farmland soil moisture was in a relatively saturated state. The different use levels of organic manure significantly increased soil moisture over0-60cm soil layer on milking stage of maize, but the sub-soiling was not prominent and the interplay of those two elements were not as significant. The sub-soiling and the different use levels of organic manure were outstanding over0-200cm soil layer on maturity stage of maize, but the interplay of those two elements were not significant.3Root distribution characters of maize under sub-soiling and organic fertilizer applicationCompared to the contrast, the root distribution in soil layer from0to20cm was relatively reduced, and the root dry weight, root length density, root surface area density and root volume density below20cm soil layer became greater under sub-soiling with straw incorporated and sub-soiling treatments. From the soil profile view, root dry weight density, root surface area density and root volume density below40cm soil layer under sub-soiling with straw incorporated treatment was greater than sub-soiling treatment. The reason might be that the good water and fertilization condition in this treatment promoted the root deeper growth and let the root distributed in the deeper soil layer.Volume of xylem sap was increased at silking stage after sub-soiling with straw incorporated and sub-soiling with the different use levels of organic manure treatments. Therefore, the measure of sub-soiling combined with different use levels of organic fertilizer can break the soil plough layer and build reasonable soil structures of the furrow soil. It was conducive to root fixing, alleviated the root growth space stress. The root distribution in the soil was reasonable. The root activity and ability of absorption water and nutrient were increased.4Maize leaf water status and photosynthesis response to sub-soiling and organic fertilizer applicationLeaf water potential and leaf relative water content were increased in different periods of maize growth under sub-soiling with straw incorporated and sub-soiling with organic manure. Meanwhile, above-mentioned treatments always maintained high Chlorophyll SPAD value of leaf at the early and middle stages of maize growth. The sub-soiling with straw incorporated, sub-soiling with medium and high use levels of organic manure and rotary tillage with high organic manure had significantly effective on reducing rate of the Chlorophyll SPAD value of leaf in maize later growth period. The results indicated that sub-soiling with straw or organic manure incorporated could postpone leaf senescence and thus advantageous to the output formatted.The Pn, Tr and Gs of maize were improved significantly by sub-soiling with straw incorporated. Results showed that the Pn, Tr and Gs of maize increased at different degrees after using of different levels organic manure at jointing, tasseling and milking stage of maize, and the sub-soiling was notable and the interplay of those two elements were not significant. 5Effects of sub-soiling and organic fertilizer application on maize growth and development, yield, quality and water use efficiencySub-soiling with straw incorporated and sub-soiling with medium and high use levels of organic manure significantly increased plant height, stem diameter and decreased the ratio of ear and plant height and LSI at the trumpeting, silking and filling stages of maize. At the same time, sub-soiling with straw incorporated and sub-soiling on loam improved the grain protein content, yield, water use efficiency and rain fall use efficiency to different degrees. Sub-soiling and the different use level of organic manure on clay treatments significantly increased maize yield, water use efficiency and rain fall use efficiency and the interplay of those two elements were not significant.更多还原