【作者】 朱利群；

【导师】 卞新民；

【作者基本信息】 南京农业大学 ， 生态学， 2010， 博士

【摘要】 随着农业产业结构的不断调整,畜禽养殖业在我国得到了快速发展,为农业增效、农民增收做出了重要贡献,但畜禽养殖业在快速发展的同时亦带来了诸多的问题。养殖总量的迅速增长,推动了畜禽粪便废弃物的大幅度增加,由于国内大部分养殖场环保观念弱,处理能力缺乏,导致大量畜禽粪便未能进行有效的处理利用而直接排入环境,对环境造成了严重的污染。畜禽粪便作为有机肥施入农田,不仅能够改良土壤,提高土壤肥力,而且通过参与农田生态系统的物质循环,可增加作物产量和提高品质。粪肥就近还田作为传统的农牧结合的处理方法,比较适合我国国情,在我国东北、华北等地一次性基施粪肥的现象非常普遍,而在长江下游地区部分农户也有基施粪肥的良好习惯。粪肥还田也有制约因素,而最重要则是粪肥还田后的二次污染问题,因为一定面积范围内的土壤和作物对养分的吸收能力是有限的,如果还田过量,多余的养分一定会随着水分流失或者通过变成气体等方式流失。因此,如何科学合理地施用粪便有机肥,对于维护土壤环境质量和确保农业的可持续发展具有十分重要的意义。本文通过连续二年半(五季)将不同水平的猪粪、牛粪施入水稻-黑麦草轮作系统的大田试验及一年半(三季)的盆栽试验,研究了不同类型粪肥还田下、粪肥不同还田水平下及粪肥连续还田下对水稻、黑麦草产量或生物量的影响,对水稻、黑麦草氮素吸收,及对农田土壤氮素剖面分布、氮素盈余和农田系统氮素损失的影响,旨在确定水稻-黑麦草轮作农田不同季节适宜的粪肥还田范围,在保证农田最大限度消纳养殖场粪肥及取得一定农业效益的同时,尽量减少粪肥还田对环境可能带来的二次污染,为规模化养殖场粪肥还田处理提供参考依据；本文还针对稻作区稻田水肥管理特点,构建了降雨-径流-氮素流失模拟模型,研究了不同水平粪肥施用下稻田氮素径流流失的风险,比较了稻田在养殖场粪肥一次性基肥还田与常规化肥施用下氮素径流流失的差异。主要结论如下：1、在一定还田水平范围内,水稻和黑麦草的生物量或产量基本上都随着粪肥还田水平的提升而不断增加,但超过此范围则增加潜力不大甚至会使作物受害。对水稻而言,粪肥第一年还田时,除猪粪最高水平处理时(P5)的生物量或产量发生下降以外,其他处理下都是随着还田水平的提升而不断增加,但连续二年还田和连续三年还田时,水稻的生物量或产量的最大值明显向低水平处理方向移动,第三年甚至前移到了P2水平；对黑麦草而言,虽然第一年还田下的生物量随着粪肥还田水平的提升而不断增加,但连续二年还田时,C5处理下的生物量也出现了稍低于C4处理的现象。如果只考虑粪肥还田对作物产量或生物量的影响,猪粪还田时,第一年水稻在P3至P4间为适宜还田量,第二年在P2至P4间为适宜还田量,第三年则在P1至P2间为适宜还田量；牛粪还田时,第一年水稻在C3至C5间为适宜还田量,第二年在C2至C5间为适宜还田量,第三年则在C2至C4间为适宜还田量；对黑麦草而言,猪粪还田下,不论是第一年还是连续还田下的第二年,均以P4至P5水平为适宜还田范围；牛粪还田下,第一年以C4至C5间为宜,第二年则以C4水平为宜。2、对水稻而言,粪肥第一年还田时,除猪粪最高水平处理时(P5)水稻植株的氮素吸收量比相邻处理要低外,其他处理下的吸氮量都是随着还田水平的提升而不断增加,但随着粪肥还田水平的提升,相邻处理间氮素吸收量的增幅程度在逐渐减少；连续二年或三年还田时,水稻植株吸氮量出现了先升后降的趋势,而且最高吸氮量明显向低处理水平方向移动,第三年甚至前移到了P2水平,盆栽条件下第二年甚至出现了秧苗大量死亡的现象；对黑麦草而言,虽然第一年还田下的植株吸氮量均随着粪肥还田水平的提升而不断增加,但连续二年还田时,C5处理下的植株氮素吸收量也出现了低于C4处理的现象。不论是猪粪还是牛粪还田,三年大田水稻的氮素农学利用率、水稻-黑麦草轮作第一年和第二年的氮素回收利用率及土壤依存率均随着粪肥还田水平的提升而不断降低。3、水稻-黑麦草轮作体系粪肥连续还田下,三年中每季作物收获后不同土层土壤全氮含量均表现为表层最高,越往深层其含量越低,从表层到20cm土层下降较快,而20cm以下土层下降较缓慢,每季作物收获后同一土层中土壤全氮含量基本上随着粪便还田水平的提升而不断增加,而且越往深层,不同还田水平间的差异性越小；第一年水稻收获后,粪肥不同还田水平下的土壤全氮含量基本保持在同一水平的土层主要分布在20-50cm,黑麦草收获后则下降到了30-50cm土层,第二年的黑麦草收获后,甚至下降到了40-50 cm土层,而到第三年的水稻收获后已基本没有全氮含量在不同粪肥还田水平下处于同一水平的土层。不论粪肥还入大田一年后还是两年后,水稻-黑麦草轮作系统土壤耕作层的氮素含量均高于土壤背景值,耕作层土壤氮素含量和氮素盈余量均随着粪便还田水平的提升而不断增加,同一还田水平下,二年后土壤耕作层含氮量均高于一年后的土壤含氮量,且还田水平越高,两者间的差异就越大。4、不论是猪粪还是牛粪还田处理,不论是第一年稻季、黑麦草季还是第二年稻季、黑麦草季或第三年稻季,抑或是第一年或第二年的轮作周年,水稻-黑麦草轮作系统的氮素损失量和损失率基本上均随着粪肥处理水平的提升而不断增加；和水稻-黑麦草轮作第一年稻季、黑麦草季或周年的氮素损失率相比,第二年稻季、黑麦草季或周年的氮素损失率普遍更高,但差异不大。综合粪肥还田下的农业效益及对环境的影响,水稻-黑麦草轮作系统第一年稻季猪粪的适宜还田量在P3(纯氮876kg/hm2)水平左右,牛粪为C3(纯氮876kg/hm2)水平左右,第一年黑麦草季猪粪的适宜还田量在P4(纯氮552kg/hm2)至P5(1104kg/hm2)水平之间,牛粪为C4(纯氮808kg/hm2)水平左右；第二年稻季猪粪的适宜还田量在P2(纯氮438kg/hm2)水平左右,牛粪在C2(纯氮438kg/hm2)至C3(纯氮876kg/hm2)水平之间,第二年黑麦草季猪粪的适宜还田量在P4(纯氮552kg/hm2)水平左右,牛粪仍为C4(纯氮808kg/hm2)水平左右；水稻-黑麦草轮作系统第三年稻季猪粪的适宜还田量在P1(纯氮219kg/hm2)至P2(纯氮438kg/hm2)水平之间,牛粪则在C2(纯氮438kg/hm2)水平左右。5、不论是施用化肥,还是一次性基施牛粪,抑或是施用不同水平的牛粪,水稻生长期的氮素径流流失量与降雨量间均存在显著的线性相关性,但是有时也会产生较大的偏差；牛粪施用下的氮素径流流失量均明显小于化肥施用下的流失量；高水平牛粪施用下稻田氮素径流流失量明显比中等水平牛粪施用下的氮素径流流失多,中等水平牛粪施用下的氮素径流流失量又明显比低水平下的要高。更多还原

【Abstract】 With the adjustment of agricultural industrial structure,livestock and poultry breeding industry develops rapidly which contributes to increasing agricultural benefits and peasants incomes.On the other hand, many problems come following with the breeding industry. There are more and more animal manure waste produced because of rapidly expanding of livestock production.Because of lack of environmental protection conception and valid waste disposal approaches of a great number of breeding farms in china, most of the animal waste discharged directly into environment without effective disposal and reuse, which result in tremendous environmental pollutions. Applying manure to field has a few positive functions. It could amend soil conditions, improve soil fertility, as well as increase crop yield and improve product quality by way of participating the matter cycling of the agro-ecosystem. As a traditional treatment in the coordination of cropping and breeding, manure application to field is suitable for the practical production in our country. Only base organic manure application to field has become more and more popular in Northeast and North China, and some peasants applly same in downstream regions of Yangtze River. Meanwhile, secondly pollution comes consequently, acting as a negative function. Because of limited uptake capacity of soil and crops in a certain region or a certain scale, surplus nutrient would lapsed followed by water or evaporated by gaseous from the excessive manures. Thus, how to apply manures to field scientifically is essential to maintain a high quality environment and insure a sustainable agricultural production.By means of applying different levels of cattle manure and pig manure to rice ryegrass rotation system for two and a half years(five seasons) under field experiments,and one and a half years (three seasons) under potted experiments, the paper studies the effects on yield or biomass of rice and ryegrass, nitrogen uptake by rice and ryegrass plants, nitrogen distribution in soil profile, nitrogen surplus and nitrogen loss of field systems caused by applying different types of manure to field, different levels of manure to field and manure to field continuous. It is aimed to determine the appropriate scope of manure applying to field, ensuring the maximum elimination on manures from breeding farms and gaining some agriculture benefits, while minimizing potential secondary pollution on the environment of manure application to field. It also provides a reference for large-scale breeding farms to return manure to field. According to the traits of the characteristics of water and nutrient management of rice cultivation in rice cropping regions, the paper also constructs a rainfall-runoff-nitrogen loss simulation model.We study the nitrogen runoff loss risk under different levels of manure application, compared the distinction of nitrogen runoff loss of paddy field between only base manure application to field and the conventional fertilizer application. The main conclusions are as follows:1、In a certain range of manure application to field, the biomass or yield of rice and ryegrass increases basically with the enhance of manure application level. Over this range, the increasing potential of yield will be much less, even would make crops suffered. As far as rice is concerned, it’s biomass or yield increase with the enhance of manure application level in addition to that of the highest level of pig manure (P5) in the first year of manure application to field. But the rice biomass or yield decline significantly to the low levels when manure application two or three years consecutively, the third year’s decline points even move to the P3 level. As far as ryegrass is concerned, though biomass increase with the enhance of manure application level in the first year of manure application to field, biomass under C5 treatment has been slightly lower than that of C4 treatment when manure application two years consecutively. According to the influence on crop yield or biomass by applying manure to field, the suitable pig manure applying amount in rice season of the first year in rice- ryegrass cropping system is between P3 and P4, P2 to P4 in the second year, P1 to P2 in the third year; the suitable cattle manure applying amount in rice season of the first year in rice- ryegrass cropping system is between C3 and C5, C2 to C5 in the second year, C2 to C4 in the third year. In terms of ryegrass, the appropriate amount of pig manure applying to field is between P4 to P5 both in the first year and second year, the appropriate amount of cattle manure applying to field is between C4 and C5, C4 in the second year.2、As far as rice is concerned, the nitrogen load absorbed by rice plants increases continuously with the promotion of manure application level in the first year in addition to that of the highest level of pig manure (P5), but the increasing degree becomes smaller gradually between adjacent treatments with the promotion of manure application level. The nitrogen load absorbed by rice plants had appeared the trend of rising first and falling later when manure application two or three years consecutively, the highest nitrogen load absorbed by rice plants of nitrogen obviously moved to the low level treatment, even moved to P2 treatment in the third yearl. Most of the rice seedlings were dead indeed under potted experiment in the second year. As far as ryegrass is concerned, the nitrogen load absorbed by ryegrass plants increases continuously with the promotion of manure application level in the first year, though that of C5 level is lower than that of C4 level in the second year. In spite of pig manure or cattle manure, nitrogen agronomy efficiency of field rice during three years, nitrogen recovery efficiency and soil dependence rate of rice-ryegrass rotation period in first or second year are all continuously decreased by the promotion of manure treatment level.3、With manure application to field continuous in the rice-ryegrass rotation system, they appeared that the total nitrogen content in the surface of different soil layer was highest, lower content in the deeper soil. The total nitrogen content descend quickly between surface and 20cm soil layer, slowly below 20cm soil layers after harvest every season in the three years. The soil total nitrogen in the same soil layer after harvest every season increased with the promotion of manure treatment level, deeper the soil, smaller the difference between different treatments. After rice harvest in first year, the soil total nitrogen content of 20-50cm soil layer basically keep in the same level under different treatment level, and that of ryegrass decreased to 30-50cm soil layer. After the ryegrass havest in second year, the nitrogen content decreased to 40-50cm, then there was no soil total nitrogen content keeping in the same level under different manure treatment after rice harvest in the third year. In spite of one or two years after manure application, the nitrogen content of the cultivated layer in the soil of rice-ryegrass rotation system were all higher than the soil background values. The nitrogen content and nitrogen surplus of cultivated layer continuously increased with the promotion of manure application level. The nitrogen content of cultivated layer after two years application was higher than that of one year, higher the manure application, larger the difference of the nitrogen content between one year later and two years later.4、In spite of pig manure treatment or cattle manure treatment, rice season or ryegrass season in the first year or second year, rice season in the third year, or rice-ryegrass rotation period of the first year or second year, nitrogen loss amount and rate of rice- ryegrass rotation system continuously increased with the promotion of manure applying level. Compared with that of rice season, ryegrass season, rotation period of rice- ryegrass rotation system in the first year, the nitrogen loss rate of rice- ryegrass rotation system in the second year were higher generally, which had little difference. According to agriculture benefits and the effects on environment by applying manure to field with various levels, the suitable pig manure applying amount in rice season of the first year of rice-ryegrass cropping system was about P3 (876kg/hm2), while the cattle manure was about C3 (876kg/hm2); the suitable pig manure applying amount in ryegrass season of the first year was between p4 (552kg/hm2) and P5 (1104kg/hm2), while the cattle manure was about C4 (808kg/hm2). The suitable pig manure applying amount in rice season of the second year of rice- ryegrass cropping system was about P2 (438kg/hm2), while the suitable cattle manure was between C2 (438kg/hm2) and C3 (876kg/hm2); the suitable pig manure applying amount in ryegrass season of the second year was about P4 (552kg/hm), while the suitable cattle manure was still about C4 (808kg/hm2). The suitable pig manure applying amount in rice season of the third year of rice-ryegrass cropping system was between P1 (219kg/hm2) and P2 (8438kg/hm2), while the suitable cattle manure applying amount was about C2 (438kg/hm2)5、In spite of applying fertilizer to field or applying only base cattle manure to field,or cattle manure of various levels, there were significant linear correlation between nitrogen runoff loss and rainfall during the rice growing season, though they sometimes displayed large deviation. Nitrogen runoff loss from paddy field under cattle manure application was much less than that of fertilizer application. Nitrogen runoff loss from paddy field under high level of cattle manure application was significant higher than that of middle level; middle level was significant higher than that of low level.更多还原