【作者】 李勇；

【导师】 徐阳春；

【作者基本信息】 南京农业大学 ， 植物营养学， 2007， 硕士

【摘要】 本试验通过在江苏省盐城市农科院试验场2005年和2006年两年的田间试验，研究了常规淹水栽培、覆盖薄膜旱作栽培、覆盖秸秆旱作栽培和裸地旱作等不同栽培方式下，稻麦轮作系统中作物生物学特征，氮肥利用率差异，土壤矿质氮动态变化，旨在阐明水稻栽培方式对稻麦轮作系统中土壤供氮特征及其对作物的生长影响机制，为提高氮肥利用效率和增加土壤肥力提供解决方法，并为水稻旱作进一步推广提供理论依据。研究结果表明，与常规水作相比，覆盖秸秆旱作水稻能够达到或超过常规淹水栽培水稻的产量，05年比常规水稻增产13％，06年与常规水稻产量相当。水稻旱作有利于后茬大麦增产，旱作水稻后茬盖草处理大麦产量最高，分别比水作后茬、覆膜后茬和裸露后茬增加23％，4％和14％。水稻覆盖秸秆旱作能显著提高稻麦轮作系统中土壤生产力，两年盖草系统生产力平均比水作系统、覆膜系统和裸露系统高13％，10％和23％．不同栽培方式下水稻氮素的累积研究表明，覆盖秸秆旱作水稻的氮素累积量达到或超过常规水作水稻，处理间差异表现为：盖草旱作处理＞水作处理＞覆膜旱作处理＞裸露旱作处理。旱作水稻促进后季大麦对氮素的吸收累积量，两年盖草后茬大麦氮素累积量平均比水作后茬、覆膜后茬处理和裸露后茬高出21％、6％和14％。作物对氮肥吸收利用率因处理不同而异，秸秆覆盖旱作水稻的氮肥利用率与传统淹水水稻氮肥利用率相当，达34％-41％；覆盖地膜和裸地旱作水稻氮肥利用率介于22％-26％，显著低于传统水作处理。水稻旱作提高了后茬大麦的氮肥利用率，两年覆盖秸秆后茬大麦氮肥利用率分别比水作后茬、覆膜后茬和裸露后茬高出38％、3.6％和16.2％。对水稻生育期土壤氮素变化的研究表明，水稻移栽后20-100d水作处理0-20cm土壤铵态氮显著高于旱作处理，两年平均高49％。就旱作处理而言，05年盖草处理略高于其它两处理，06年表现为盖草＞覆膜＞裸露。硝态氮垂直分布存在明显梯度，随着土壤层次的加深而递减。水稻生育期，0-20cm和20-40cm两层中旱作处理硝态氮高于水作处理，且以盖草处理含量最高，覆膜处理次之；而在40-60cm，60-80cm层中，盖草处理远低于其它两个旱作处理。对后茬大麦土壤氮素的研究发现，各处理土壤铵态氮差异不显著，且在垂直分布上各层次变异较小；而土壤硝态氮在0-20cm，20-40cm，40-60cm，60-80cm层依次下降。比较不同栽培方式水稻收获后0-20cm层土壤矿质态发现，盖草处理和覆膜处理分别比水作处理提高了90.4％和65.2％。土壤微生物生物量因水稻栽培方式不同而异。盖草处理微生物量碳分别比水作、覆膜和盖草处理高出50.7％、18.1％和31.9％；微生物量氮高55.4％、11.83％和48.9％。比较五年前后土壤肥力的变化发现，水作和盖草处理显著提高了土壤有机质和全氮含量，有机质分别比五年前试验开始时提高了10.6％和14.3％；全氮分别增加了19.8％和28.6％。而覆盖地膜与试验前相比，土壤有机质下降了15.2％。全氮下降了12.1％。总之，水稻覆盖地膜旱作水稻在一定程度上改变了土壤氮素存在形态和含量，增加了微生物量含量，提高了土壤肥力，从而改变作物的氮肥利用率和产量，在农业生产上具有重要的推广价值。更多还原

【Abstract】 In order to provide a theoretical basis for rice cultivation mode in aerobic soil condition, a field experiment was conducted in Yancheng Academy of Agriculture Science, Jiangsu province from 2005 to 2006 and such parameters were determined as plant biological traits, nitrogen use efficiency differences, mineral nitrogen dynamic changes.In rice season, the treatments included a waterlogged cultivation （W）, aerobic cultivation with plastic film mulching covered （PF）, aerobic cultivation with rice straw mulching covered （RS） and aerobic cultivation without any mulching （B）. After rice season barley was planted with nothing mulched in all treatments. Accordingly, the post-barely treatments was marked as post-waterlogged soil treatment （PW）, post-plastic film mulching treatment （PPF）, post-rice straw mulching treatment （PRS） and post-no mulch treatment （PB）, respectively.Compared with W treatment, RS treatment could meet or exceed yields of rice. In year 2005 the yields of rice grains in RS was 13% higher than W, and in year 2006 both the treatments had a same yield. Also, rice cultivation in aerobic soil condition had a good effect on post barely grain yields compared with W. Treatment. PRS had a highest grain yield that was 23%, 4% and 14% higher than PW, PPF and PB, respectively. Rice cultivation in aerobic soil with rice straw mulching significantly increased soil productivity of rice-barely system, which was 13%, 10% and 23% higher than PW, PPF and PB, respectively.More or a same nitrogen amount was accumulated in rice in RS treatment compared with W treatment. On average year, total nitrogen accumulation in plants was found in the order of RS＞W＞PF＞B. Rice cultivation in aerobic condition significantly increased post barely to accumulate nitrogen. Barely in PRS treatment accumulated a maximum nitrogen that was 21%, 6% and 14% higher than PW, PPF and PB, respectively.Fertilizer nitrogen use efficiency by rice in RS treatment could meet or exceed W treatment, but fertilizer nitrogen use efficiency of rice in treatment PF and B was significantly lower than traditional paddy rice. After two years’ study, it was found fertilizer nitrogen use efficiency by barley could be improved by pre-aerobic cultivation rice. Maximum fertilizer nitrogen use efficiency was found in PRS, and it was 38%, 3.6% and 16.2% higher than PW, PPF and PB, respectively.Soil NH₄⁺-N content in W was much higher than aerobic cultivation of rice during the rice growth period. In year 2005, soil NH₄⁺-N had no significant difference in vertical distribution, but soil NH₄⁺-N decreased rapidly from 0-20 cm to layer 60-80 cm in year 2006. W treatment had maximum NH₄⁺-N in each layer. In layer 0-20 cm and 20-40 cm, NH₄⁺-N performed as, RS＞PF＞B, while PF had a NH₄⁺-N content higher than RS and B in layer 40-60 cm and 60-80 cm. Rice cultivation mode had a profound effect on surface soil NO₃^--N content during rice growing periods. On average year, NO₃^--N in W treatment significantly was lower than in aerobic condition. Of all aerobic treatments, RS had a higher soil NO₃^--N than other two treatments in year 2005, and in year 2006 the soil NO₃^--N contents were in the order of RS＞PF＞B. There existed a vertical distribution of soil NO₃^--N content that was reduced from 0-20 cm to 60-80 cm layer. Soil NO₃^--N in aerobic condition was much higher than in W in layer 0-20 cm and 20-40 cm and RS had a higher NO₃^--N content than PF and B in these two layers. But in layer 40-60 cm to 60-80 cm, RS had a much lower NO₃^--N content than the other two aerobic treatments. Soil NH₄⁺-N did not have any differences during barely growing periods between each treatment, and no variation in vertical directional distribution either. Unlike soil NH₄⁺-N in barely-grown season, NO₃^--N had a grade concentration that was reduced from surface to layer 60-80 cm. Soil mineral nitrogen measured before rice transplanting and barley sowing each year, it was found that PRS and PPF treatment increased soil mineral nitrogen by 65.4% and 90.2%, respectively, compared with W.Rice with straw mulching significantly improved soil microbial biomass. RS, for example, had maximum microbial biomass C, and it was 50.7%, 18.1% and 31.9% higher than W, PF and B, respectively. Also RS had maximum microbial biomass N, and it was 48.9%, 55.4% and 11.83% higher than W, PF and B, respectively. By comparing the changes of soil fertility in different rice cultivation modes for five years, it was found that rice cultivation mode had a profound impact on soil fertility. W and RS significantly increased soil organic matter by 10.6% and 14.3%, total soil nitrogen by 19.8% and 28.6%, respectively, compared with those at the beginning of the experiment. However, PF reduced soil organic matter and total soil nitrogen by 15.2% and 12.1%.We conclude that rice cultivation in aerobic soil with straw mulching could improve soil fertility, and thus assure a higher crop production and water use efficiency.更多还原