【作者】 褚贵新；

【导师】 沈其荣；

【作者基本信息】 南京农业大学 ， 植物营养， 2003， 博士

【摘要】 我国是淡水资源非常缺乏的一个国家，65～80％的淡水用于农业灌溉用水。传统的水稻淹水栽培对淡水资源的消耗量非常巨大，但是水分利用效率非常低下。旱作水稻作为一种全新的农业节水栽培方式，一般可以节约水资源90～100％，不但具有巨大的节水效益，而且可以获得和淹水栽培相同或相近的产量。水稻（Oryza sativa L., Wuyujing 99-15）旱作的成功实践使得旱作水稻可以和豆科作物间作，而豆科作物／禾本科作物间作系统往往具有明显的产量优势和高的资源利用效率，也是可持续农业发展的重要内容。花生（Arachis hypogaea L., Zhenyuanza 9102）是一种重要的经济作物，本研究采用大田小区实验和¹⁵N同位素标记盆栽实验对旱作水稻／花生间作这一新的种植方式在2001～2002进行了研究，旨在探索实现旱作水稻的新途径，揭示旱作水稻和花生间作的产量优势，并研究了旱作水稻／花生间作系统的氮素供应特征，以及这一种植方式对土壤氮素肥力的影响以及对后茬小麦生长的影响。 1．通过2001～2002两年田间小区试验，对旱作水稻与花生间作的产量效益进行了比较研究。研究结果表明，水稻／花生间作具有明显的产量优势，通过间作可以提高产量18～41％。间作中起增产作用的作物是水稻，在水稻／花生为3∶3和4∶2两种间作方式下水稻的相对产量分别比单作水稻产量高29～37％和38％，间作对花生产量的影响不显著，但间作系统中增加水稻的种植比例会导致花生产量的下降。水稻与花生间作可以显著提高水稻的氮素含量，在水稻单作、水稻／花生间作比例分别为3∶3和4∶2的三种种植方式下，水稻的叶片含氮量分别为21.2、26.9和22.8 g kg^-1，间作比单作分别增高27.1％和7.6％，经方差分析在P=0.05的水平有显著差异。与花生间作可以提高水稻叶片的叶绿素含量，其叶片的叶绿素含量显著的高于单作水稻的，间作花生的含氮量与单作比较没有明显差异，花生间作后其叶片含氮量有一定程度的下降。间作系统中水稻是优势作物种，竞争能力大于花生，通过与花生间作提高了水稻的有效分蘖数，显著增加了水稻的单稳重和千粒重。 2．采用根系分隔处理的研究方法和¹⁵N同位素稀释标记示踪法，在不同氮素水平下研究了水稻／花生间作系统的氮素营养优势，间作花生的生物固氮效率，2001年试验表明：1)水稻和花生间作有产量优势和氮素营养优势，在0、225和300kg N hm^-2三个氮肥水平，根系不分隔处理（间作）的水稻生物量分别比分隔处理的高30.03、10.1和2.2％；水稻氮素吸收量分别比根系分隔处理的高74.03、16.93和23.2％；2)一一一一一g垫些垫燮鳖垫擎勇鹭鬓花生在225和3的kg Nhm一2氮素水平下，分隔处理和不分隔花生固氮量分别为38·11、40·97%和14·81、20.49%，间作能提高花生固氮效率。2002的实验进一步在15、75和150 kg Nhxn一三个氮肥供应水平条件下花生生物固氮间作系统的氮素吸收。结果表明，在巧和75 kghm一两个氮素水平下，间作水稻比单作水稻的干物质量分别增加了23 .5和12.2%，在尸=0.05的水平有显著差异。间作水稻和单作水稻的氮素吸收量分别为134.7、142.8和1173、131.2 mg株一，，间作水稻的氮素吸收量分别比单作增加14.8和8.8%。不同栽培方式对花生的干物质积累和氮素吸收影响很小。在15认75和15 kgNhm一2三个氮素水平下，间作花生和单作花生的固氮效率（%NDFA）分别为50.7、53.3、76.10，0和35.4、56.5、72.8%，花生的固氮效率随氮肥水平的增加而显著降低，在低氮肥水平下的生物固氮显著高于高氮肥水平的，间作对增加和刺激花生的生物固氮有显著的促进作用，尤其是在氮肥供应水平高的情况下，间作能明显提高花生的生物固氮效率（%NDFA）。 3.用花生叶片”N富积标记法和”N同位素稀释法（ID法）两种不同方法比较研究了对水稻/花生间作系统中花生向水稻的氮素转移，不同氮肥供应水平对氮素在水稻/花生间作系统转移的影响，同时，用’加的富积标记法研究了花生根系腐解对间作系统氮素转移的贡献。研究结果如下:在225和300 kg Nhm一的氮肥施用水平条件下，采用”N花生叶片标记法（%NT）和稀释法（o/oNDFL）都证明在水稻花生共生期间花生固氮量的2一3.5%转移到水稻体内.与花生间作能明显的提高水稻干物质产量和氮素吸收量，在15、75和1 50 kg N hm-2三个氮肥施用水平条件下，间作水稻和单作水稻的氮素吸收量分别为134.7、142.8、255.2 mg袜l和227.3、132.2和174.3mg株一，，间作水稻的氮素吸收量分别比单作增加14名、9.6和7.9%.不同栽培方式对花生的干物质积累和氮素吸收影响很小.间作系统中的氮素转移率（o/oNDFL）和转移量在15、75和150 kgN腼一3个氮素水平分别为12.2、9.2、6.20，0和16.3、13、10.4 mg株一’，氮素转移率和氮素转移量随着氮肥水平的增加而显著减少. 花生和水稻叶片标记氮素双向转移试验表明，在15、75、1 50 kgN一hm一2三个氮肥水平下，间作水稻的干物质积累量和氮素吸收量分别为9.4、12.1、13.59株”和207.4、241.2、259.4mgN株一，，分别比单作水稻增加了21一290，0、7一296/0、18-30%和43.43、45.72、犯名1更多还原

【Abstract】 Rice is one the three most important crops (rice, wheat and maize) in China and it accounts for 40% of the summer crops, about 40 million hectare per year. Waterlogged cultivation of rice is a traditional way, which can ensure the rice yield to be very high and long-term stable. However, more than 80% of the freshwater used in agriculture finds its way to rice production in waterlogged soil in China. In Jiangsu province, for example, where it receives 800~ 1000mm precipitation annually, irrigation of 10,500~ 15,000 m3 of freshwater per hectare is still needed for one crop season of rice and more irrigating freshwater is needed in the area with less rainfall. Much work has been done on water-saving cultivation of rice crop, i.e., intermittent irrigation, which saved 20~60% of freshwater compared with traditional waterlogged cultivation, varying with the different precipitations in different areas.A novel cultivation system of rice crop in aerobic soil is showing its great potential in water saving agriculture, especially in the areas which receive more than 800 mm of precipitation annually. The rice cultivated in aerobic soil is a complete revolution in the rice cultivation system, in which the rice crop (not upland variety but traditional paddy rice variety in waterlogged soil with high yield) is grown during whole growth stage in a soil with water content being 70~85 % of water holding capacity (WHC). Our previous three years’ field experiments showed that almost the same grain yields of rice crop could be obtained in aerobic cultivation as in waterlogged only if the soil was mulched with crop straw. In Jiangsu province, for example, the yield of rice grain of 8738 kg hm’2 in aerobic cultivation could be obtained and only 11% reduction was found compared with that in waterlogged cultivation with the same rice cultivars. About 90~100 % of freshwater irrigated could be saved in aerobic cultivation compared with waterlogged one and 11% reduction in grain yield of rice cultivated in aerobic soil is nothing in terms of the freshwater saved.The novel cultivation of paddy rice variety in aerobic soil reveals a great potential not only for water-saving agriculture but also for the rice intercropping with legumes, both of which are closely related to sustainable development of agriculture. In this study, field experiments were carried out to investigate yield advantages in intercropping system of peanut with rice crop cultivated in aerobic soil in 2001 and 2002 and the effects of intercropping system on soil N fertility were also studied in field condition. Pot experiments were then done to examine the biological nitrogen fixation (BNF) by peanut and N transfer from peanut to rice in the intercropping system using 15N-isotope dilutionmethod with N fertilizer application rates of 15, 75, 150, 225 and 300 kg N hm-2 in 2001 ~ 2002, and the contribution of peanut root decomposition to N transfer was investigated as well. The main results were as follows:1. Two-year field experiments showed that the relative advantage of intercropping, expressed as land equivalent ratio (LER), was 1.41 in 2001 and 1.18-1.36 in 2002, respectively. Yield of rice was significantly increased in intercropping system while that of peanut were not significantly different in intercropping and monocropping system. The yields of rice grain and peanut, for example, were increased by 29~38 % and 4~7% in intercropping system compared to the respective component crop in monocropping system, respectively. The N concentration of rice (21.2 g kg"1) under monocropped condition was significantly (P=0.05) lower than under intercropped (26.9 g kg"1) condition, while there was no significant difference of N concentration of peanut between mono- and intercropping. Compared to the rice in monocropping system, an increasing of 27.4 % of N concentration in rice plant was obtained in intercropping when the rice was harvested, which resulted in a higher chlorophyll content of the rice leaves. Thus, the chlorophyll content of rice leaves were更多还原