【作者】 高茂盛；

【导师】 廖允成；

【作者基本信息】 西北农林科技大学 ， 生态学， 2010， 博士

【摘要】 由于独特的气候资源和土壤条件,黄土高原已被确定为中国苹果的两大优生区之一。但境内降水量有限,加之土壤管理措施的不合理,干旱缺水及土壤贫瘠已成为限制该区域苹果业健康可持续发展的重要因素。为此,本研究将保护性耕作技术引入到果园中,以翻耕裸地为对照,对免耕秸秆覆盖、翻耕秸秆覆盖、深松秸秆覆盖、免耕生草及免耕裸地处理下果园土壤水分环境、土壤理化性状、生物性状指标进行了测定,系统研究了保护性耕作措施对苹果园土壤保蓄水性能、土壤养分含量及有效性的影响,探明了果园实施保护性耕作措施后的水土效应,为该区域果园构建水土保持型土壤管理模式提供了理论与技术依据。本研究取得的主要结论有:（1）对不同树龄果园及荒草地0-5m土层内土壤水分含量进行测定后表明,10年以上树龄果园0-5m土层内土壤有效贮水量开始出现过耗现象,10、15及20年树龄果园0-5m土层内土壤水分过耗量分别为2.09、100.65及154.51 mm,土壤干燥化速度分别为0.21、6.71及7.73 mm﹒a-1。10年和15年果园0-5 m土层平均土壤干燥化指数达到二级,属于轻度干燥化,20年树龄果园0-5m土层平均土壤干燥化指数为66%,属于中度干燥化,10年树龄果园是土壤发生干燥化的一个界限。20年树龄果园4-10月各月0-5m土层平均土壤干燥化指数在54-94%之间,属于轻度或中度干燥化,降水补充并不能恢复20a果园深层土壤的水分状况。（2）秸秆覆盖各处理及生草处理降低了土壤容重,改善了土壤的孔隙状况,增加了土壤的贮水库容,特别是深松秸秆覆盖处理,深松打破了土壤犁底层,显著降低了20-40cm土层土壤容重,深松秸秆覆盖处理20-40cm土层土壤容重较翻耕裸地处理低0.1 g.cm-3,试验进行3年后,深松秸秆覆盖处理土壤饱和贮水量增加了3.1%。对不同保护性耕作处理果园土壤水分含量测定表明,秸秆覆盖提高了土壤的保蓄水性能,在降水较少的2008年5月份及2009年4月份免耕秸秆覆盖处理1m土层内土壤贮水量分别较翻耕裸地高53.81mm及36.4mm,深松秸秆覆盖处理较翻耕裸地高39.65mm及26.6mm,翻耕秸秆覆盖处理较翻耕裸地高34mm及22.4mm;在降水较多的2008年9月份及2009年8月份,1m土层内土壤贮水量也以深松秸秆覆盖及免耕秸秆覆盖处理为最高,显示出深松秸秆覆盖及免耕秸秆覆盖处理较强的保蓄水性能。免耕生草处理虽然降低了土壤容重,改善了土壤的孔隙状况,增加了土壤的贮水库容,但由于三叶草生长本身需要耗用一定的土壤水分,在降雨量较少的年份或季节,存在与果树争夺水分的情况,2008年5月份果园1m土层内土壤贮水量较翻耕裸地低25.75mm。在2008年5月份及2009年4月份免耕裸地处理1m土层土壤贮水量高于翻耕裸地,而在2008年9月份及2009年8月份却相反,翻耕裸地高于免耕裸地,说明免耕的保水效果大于翻耕,而翻耕的蓄水效果好于免耕。（3）试验期间,秸秆覆盖各处理及生草处理均不同程度地提高了土壤有机质含量,在0-20cm土层,2008年及2009年翻耕秸秆覆盖、深松秸秆覆盖、免耕秸秆覆盖及免耕生草处理平均土壤有机质含量较翻耕裸地处理高4.75 g.kg^-1、4.76 g.kg^-1、4.53 g.kg^-1及3.35 g.kg^-1。各处理对土壤全量养分的影响同土壤有机质,秸秆覆盖及生草提高了土壤中全量养分的含量,以深松秸秆覆盖、翻耕秸秆覆盖及免耕秸秆覆盖处理增加幅度为最大,同时果园实施保护性耕作措施后,土壤的实际供肥能力也有了很大的提高,在0-40cm土层,2009年深松秸秆覆盖、翻耕秸秆覆盖、免耕秸秆覆盖及免耕生草处理土壤速效氮含量及速效磷含量分别比翻耕裸地高13.25 mg.kg^-1、12.45 mg.kg^-1、6.17 mg.kg^-1、4.92 mg.kg^-1及33.94 mg.kg^-1、33.08% mg.kg^-1、28.61 mg.kg^-1、12.61 mg.kg^-1。（4）秸秆覆盖各处理和生草处理较翻耕裸地处理相比,均不同程度地提高了土壤细菌和真菌数量,各处理以翻耕秸秆覆盖、免耕秸秆覆盖及深松秸秆覆盖处理为最高。各处理0-40cm土层平均土壤蔗糖酶活性、脲酶活性及过氧化氢酶活性均以深松秸秆覆盖处理为最高,与翻耕裸地处理差异显著。2009年5月份及10月份0-40 cm土层深松覆草、翻耕覆草、免耕覆草及免耕生草处理平均土壤蔗糖酶活性分别比翻耕裸地高0.96 ml.g^-1.d^-1、0.89 ml.g^-1.d^-1、0.76 ml.g^-1.d^-1、0.60 ml.g^-1.d^-1,土壤脲酶活性比翻耕祼地高0.86 mg.g^-1.d^-1、0.91 mg.g^-1.d^-1、0.36 mg.g^-1.d^-1、0.22 mg.g^-1.d^-1,土壤过氧化氢酶活性比翻耕裸地高3.19 mL.g^-1、2.22 mL.g^-1、1.65 mL.g^-1、1.12 mL.g^-1。（5）对土壤养分性状、生物性状进行相关分析后表明,土壤0-40cm土层有机质含量与同层土壤全氮、全磷、全钾、速效氮、速效磷、速效钾含量,蔗糖酶、脲酶、过氧化氢酶活性及细菌、真菌数量都达到极显著相关,与放线菌数量呈负相关,但没有达到显著相关水平。运用主成分分析方法对各处理土壤的综合肥力进行了评价分析,各处理综合肥力效应大小为:深松秸秆覆盖>翻耕秸秆覆盖>免耕秸秆覆盖>免耕生草>免耕裸地>翻耕裸地,表明秸秆覆盖及生草措施对土壤肥力的提高起着重要作用。（6）保护性耕作措施显著提高了苹果的产量及品质,2009年深松秸秆覆盖处理苹果百果重较翻耕裸地处理高1.11 kg,含糖量较翻耕裸地处理高2.27%;翻耕秸秆覆盖、免耕秸秆覆盖处理百果重较翻耕裸地高0.76 kg及0.88 kg,含糖量较翻耕裸地高1.74%及1.79%。（7）本试验研究表明,在果园土壤保蓄水效应方面,以免耕秸秆覆盖及深松秸秆覆盖为最好,在果园土壤肥力方面,以深松秸秆覆盖及翻耕秸秆覆盖处理为最好。综合水土效应及以减化栽培节能为目的,该区域果园土壤管理模式以深松秸秆覆盖为最好,但在具体的果园土壤管理中,应注意深松与免耕土壤耕作方式的轮换。更多还原

【Abstract】 Loess Plateau has been identified as one of two apple’s eugenics district due to its unique climate and soil conditions of resources in China. But within the limited precipitation, coupled with the unreasonable soil management practices, drought and poor soil have become an important factor to restrict the development of healthy and sustainable apple industry in the region. Therefore, this study was conducted to findout the effects of conservation tillage on the apple orchards of this region. Different treatments were used, including no-tillage with straw mulch, plow tillage with straw mulch, subsoiling with straw mulch, grass mulch and no-tillage, while plow tillage was used as control.The data was recorded regarding, soil water, environment properties, soil physical and chemical properties and biological characteristics. The effects of conservation tillage on ability of water storing and preserving, content of soil nutrient and availability of soil nutrient were studied.The main conclusions obtained in this study are as follows:（1）The soil moisture contents of different age orchards and grasslands in 0-5m layer were tested, and the results indicate that the soil available water of 10 years old apple orchard in 5m layer began the behavior of over consumption while the soil moisture excessive consumption of 10, 15 and 20 years old orchard in 5m layer were 2.09, 100.65 and 154.51mm. Similarly soil desiccation rates were 0.21, 6.71, and 7.73mm. a^-1. The average SDI （soil desiccation index） of 10 and 15 years old apple orchards were up 2（mild desiccation）, The average SDI （soil desiccation index） of 20-year old orchard was 66% （moderate desiccation）, after 10 years in the orchard there will occur desiccation. 20 years old orchard showed a serious deficit of water and the average SDI between 54-94% （mild or moderate desiccation）.（2）Straw mulch treatments and grass mulch treatment decreased soil bulk density, improved the porosity of the soil, increased soil water storage capacity, especially by the treatment of subsoiling with straw mulch. Subsoiling broked the plough pan, significantly reduced the 20-40cm soil bulk density and the soil bulk density of soiling with straw mulching in 20-40cm layer was decreased by 0.1 g.cm-3compared to plow tillage. Experiment carried out three years later, showed that the soil water storage capacity of the treatment of subsoilong with straw mulching increased by 3.1%. The soil moisture content of different conservation tillage treatments were determined and showed that straw mulch improved the ability of water storing and preserving, in May 2008 and April 2009. The soil poundage in 1m layer of no-tillage with straw mulch increased by 53.81mm and 36.4mm, while of subsoiling with straw mulch was increased by 39.65mm and 26.6mm,. Similarly of plow tillage with straw mulch was increased by 34mm and 22.4mm compared to plow tillage.In September 2008 and August 2009, the soil poundage of subsoiling with straw mulch and no-tillage with straw mulch also showed more than plow tillage indicating that the treatment of subsoilong with straw mulching and no-tillage with straw mulch have the strong and preserving ability of water. The treatment of grass mulch decreased the soil bulk density, improved the porosity of the soil and increased soil water storage capacity, however, gross needs to takes a certain degree of soil moisture to grow, so grass competed for water with apple trees in the year or season when the rainfall is less, in May 2008 the soil poundage of grass mulch decreased by 25.75mm compared to plow tillage. In May 2008 and April 2009, the soil poundage of no-tillage more than plow tillage, but lower than plow tillage in September 2008 and August 2009, indicated that the ability of water storing of no-tillage was better than plow tillage and the ability of water impoundment of plow tillage was better than no-tillage.（3）From 2007 to 2009 treatments of straw mulch under different tillages and grass mulch have improved soil organic matter content. In 2008 and 2009, plow tillage with straw mulch, subsoiling with straw mulch, no-tillage with straw mulch and grass mulch increased the soil organic matter in the 0-20 cm soil layer by 4.75 g.kg^-1, 4.76 g.kg^-1, 4.53 g.kg^-1 and 3.35 g.kg^-1 compared to the treatment of plow tillage. Treatments of straw mulch under different tillages and grass mulch have improved soil total fertilizer and the increase rate of subsoiling with straw mulch, plow tillage with straw mulch and no-tillage with straw mulch was largest. At the same time after the implementation of conservation tillage in orchard, the actual capacity of the soil for fertilizer has also been greatly improved, in 0-40cm soil layer in 2009, the soil available N content of subsoiling with straw mulch, plow tillage with straw mulch, no-tillage with straw mulch and grass mulch increased by 13.25 mg.kg^-1, 12.45 mg.kg^-1, 6.17 mg.kg^-1, 4.92 mg.kg^-1 and the soil available P content of subsoiling with straw mulch, plow tillage with straw mulch, no-tillage with straw mulch and grass mulch increased by33.94 mg.kg^-1, 33.08% mg.kg^-1, 28.61 mg.kg^-1, 12.61 mg.kg^-1 compared to plow tillage.（4）Straw mulch under different tillage and grass mulch have increased soil bacteria and fungi compared to plow tillage and effect of subsoiling with straw mulch on increasing soil bacteria and fungi was highest, followed by plow tillage with straw mulch, no-tillage with straw mulch and grass mulch. Affect of treatments on soil enzyme activity same as soil microorganism, effect of subsoiling with straw mulch on the activity of soil sucrase, urease and catalase was highest in al treatments and followed by plow tillage with straw mulch and no-tillage with straw mulch and the difference under treatments was significant. （5）The correlation analysis of soil fertilizer characteristics, soil biological traits results, indicated that soil organic matter content in 0-40cm layer extremely significant correlation with the soil TN content, TP content, TK content, AN content, AP content, AK content, soil sucrase, soil urease , soil catalase, soil bacteria and soil fungi, and negative correlation with soil actionmycete. Principal component analysis on the integrated soil fertility was evaluated and the effect of different treatments on integrated soil fertility were: subsoiling with straw mulch>plow tillage with straw mulch>no-tillage with straw mulch>grass mulch>no-tillage>plow tillage, and also known by the composite scores that the integrated soil fertility scores of subsoiling with straw mulch, plow tillage with straw mulch and no-tillage with straw mulch were above the value, grass mulch below the average but score higher than plow tillage. The results above all indicated that straw mulch and grass mulch play an important role in improving soil fertility.（6） Conservation tillages increased fruit yield and quality of apple, 100 fruit weight of subsoiling with straw mulch increased by 1.11kg, saccharinity increased by 2.27% compared to the treatment of plow tillage; plow tillage with straw mulch and no-tillage with straw mulch increased 100 fruit weight by 0.76kg and 0.88kg, increased saccharinity by 1.74% and 1.79% compared to the treatment of plow tillage.（7） Drought and poor soil was an important factor to restrict the development of healthy and sustainable apple industry in the region. The experiments showed that the effect of no-tillage with straw mulch and subsoiling with straw mulch on ability of water storing and preserving was best and the effect of subsoiling with straw mulch and plow tillage with straw mulch on improving soil fertility was best in all treatments. Integrated soil fertility and soil water effects and to reduce energy for the purpose, the best orchard soil management in the region is subsoiling with straw mulch, and we should pay attention to subsoiling and no-tillage, soil tillage rotation in orchard soil management to improve the soil metabolism and to improve the soil nutrients levels and nutrients availability.更多还原