【作者】 杨秀春；

【导师】 刘连友； 严平；

【作者基本信息】 北京师范大学 ， 自然地理学， 2004， 博士

【摘要】 近年来,沙尘暴的频繁发生引起了全社会对土壤风蚀的广泛关注。土壤风蚀不仅是干旱、半干旱地区风沙流、沙漠化与沙尘暴灾害的重要因素,而且能够造成地表土壤颗粒在时空上的重新分布和分选,对我国农业生产活动乃至社会经济的可持续发展产生了深刻、深远的影响。在我国北方旱作农业区,由于生态环境脆弱,耕作技术简单粗放,尤其是在冬春季节,农田无植被覆盖、地表裸露、土壤干燥,再加之不合时宜的传统翻耕,造成了严重的农田土壤风蚀。所以,研究如何改变旱作农业区传统耕作技术,建立既能提高作物产量又能防治土壤风蚀的保护性耕作技术就成为促进农业持续发展和建设良好生态环境的重要途径。结合国家“十五”科技攻关项目“沙区农田、草地土壤风蚀防治技术研究”的开展,本研究的主要目的在于通过实验研究,以第一手资料定量对比旱作农业区不同保护性耕作措施在保蓄水分、促进作物生长以及防治土壤风蚀等各个方面的优劣,从而综合设计出符合我国旱作农业区生产实际的防治土壤风蚀的农田保护性耕作新技术。本实验以内蒙古太仆寺旗小河套村为研究区,在作物(油菜)发育期间布置了免耕、深松、传统翻耕、翻耕覆盖、浅耕、垄15cm(1:12)、垄25cm(1:6)、垄15cm(1:6)和垄25cm(1:24)等9种耕作措施的实验观测;在农田休闲期共布置了翻耕覆盖、传统翻耕、深松、浅耕、垄作处理、小麦高茬(45cm)、小麦低茬(10cm)、油菜高茬(45cm)、油菜低茬(10cm)、胡麻低茬(10cm)等13种耕作措施的实验观测。采用野外实地观测、风洞实验和室内数据分析等方法对以上各种耕作措施下的土壤水分、作物、近地面风况以及土壤风蚀状况等进行了系统观测。本研究在不同耕作措施土壤水分、作物、近地面风况以及土壤风蚀状况等方面的基本结论为:(1)不同耕作措施下的土壤水分状况在9种耕作措施中,油菜发育期间0~70cm深度土壤水分随时间的波动趋势基本一致;垄作处理0~70cm土壤水分含量较高,免耕、浅耕相对较低,翻耕覆盖、深松耕作、传统翻耕相对居中。秋收后,秸秆还田翻耕、深松耕作、传统翻耕、免耕低茬(茬高10cm)和免耕高茬(茬高45cm)等5种措施土壤水分随深度的波动趋势也基本一致;比较而言,免耕高茬措施0~30cm土壤水分含量较高,深松耕作和传统翻耕相对居中,秸秆还田翻耕和免耕低茬相对较低。(2)不同耕作措施对作物的影响在9种耕作措施中,翻耕覆盖措施下油菜高度、盖度最大,免耕措施下油菜高度、盖度最小,翻耕覆盖措施下油菜高度、盖度均值分别较免耕措施下高度、盖度均值的增幅为63.17%和220.00%;观测期内,9种耕作措施下单株鲜物质重量、单株干物质重量和1m2干物质重量均呈现出增大趋势,翻耕覆盖措施下单株鲜物质重量、单株干物质重量和1m2干物质重量增幅最大,免耕增幅最小;9种耕作措施中,翻耕覆盖措施的单株鲜物质重量、单株干物质重量、1m2干物质重量和分器官干物质重量最大,免耕最小;9种耕作措施中,翻耕覆盖措施不仅千粒重、茎杆重最大,而且理论产量、实际产量也最高,实际产量的增产幅度约为免耕小麦产量的23.33%。更多还原

【Abstract】 Soil erosion by wind is an important factor causing aeolian sand drift, desertification and dustand sand storms in arid, semi-arid regions. It has aroused public attention as a problem ofendangering agriculture and the development of social and economy. Because soil grain on soilsurface can be redistributed by wind in time and spatial, agricultural activities and economy mustbe influenced, especially in dry farmland area. In winter and spring season, farmland is uncoveredwith vegetation, and soil is very dry. Additionally, extensive conventional cultivation results inserious soil erosion because of fragile eco-environment. Therefore, it is important to changetraditional tillage and establish new tillage technology in order to promote sustainable agriculturaldevelopment and improve the environment.On the basis of research on wind erosion and conservation tillage at home and abroadresearch report on conservation tillage’s quantification can be provided for dry farmland areacomparing different tillage technology.Xiaohetao village in Taipusi County, Inner Mongolia,was selected as the study area. Duringthe period of crop growth, nine tillage modes were disposed in the field, including no-till, subsoiltillage, conventional tillage, plowing with stalk mulch, surface tillage, ridge tillage 15cm (1:12)ridge tillage 25cm (1:6), ridge tillage 15cm (1:6), and ridge tillage 25cm (1:24). In the period offallow farmland, thirteen tillage modes were disposed including plowing with stalk mulch,conventional tillage, subsoil tillage, surface tillage, ridge tillage, high stubble of wheat (height ofstubble is 45 cm), low stubble of wheat (height of stubble is 10 cm), high stubble of rape (heightof stubble is 45 cm), low stubble of rape (height of stubble is 10 cm), and low stubble of benne(height of stubble is 10 cm). Through field observation, wind tunnel test and data analysis, soilmoisture, crop growth, near surface wind velocity and soil erosion by wind were systematicallydiscussed in this paper. Some conclusions are drawn as follows.(1) Soil moistureDuring the growth period of rape, soil moisture from 0 to 70 cm depth of ridge tillage is thehighest in the nine tillage modes, that of no-till and surface tillage are the lowest, and that ofplowing with stalk mulch, subsoil tillage and conventional tillage was moderate.After harvesting of crop, comparing stalk returning farmland and plowing, subsoil tillage,conventional tillage, low stubble of wheat and high stubble of wheat, content of soil moisture ofhigh stubble of wheat is highest from 0 to 30 cm, those of subsoil tillage and conventional tillageare placed in the middle, and those of stalk returning farmland and plowing and low stubble ofwheat are lowest.(2) Crop growthOn the basis of field observation and data analysis, the height and coverage of rape ofplowing with stalk mulch is the largest of nine types tillage modes, those of no-till are the smallest.Furthermore, the weight of fresh matter and dry matter of individual plant and 1 square meterweight of dry matter of nine types tillage modes are all increasing with time, such are amplitude.Those of plowing with stalk mulch are the largest of all, and those of no-till are smallest.Moreover, yield of plowing with stalk mulch is also the highest, and that of no-tillage is thelowest.(3) Near surface wind velocityRoughness and friction velocity are increasing with the growth of rape in nine tillage modes.The mean roughness and friction velocity of plowing with stalk mulch is the largest, and those ofno-till are smallest.In fallow period, roughness and frictional velocity of ridge tillage 25cm (1:6) and highstubble of wheat (height of stubble is 45cm) are largest of thirteen tillage modes, its abilitypreventing soil erosion is the best;those of conventional tillage are the smallest, and its abilitypreventing soil erosion is the poorest.(4) Soil erosion by wind on farmlandAccording to the result of wind tunnel test, some conclusions are drawn for subsoil tillage,plowing, plowing and scrunching, stubble of wheat (height of stubble is 10cm), stubble ofbuckwheat (height of stubble is 10cm), stubble of benne (height of stubble is 10cm) andno-stubble. The difference of tillage modes resulted in different deflated matter in the 0-20 cmheight. The wind-eroded matter of plowing and scrunch is the largest, and that of the stubble ofbenne is the smallest. The order of wind-eroded matter for seven tillage modes is as follows:plowing and scrunching>no-stubble > stubble of buckwheat > subsoil tillage > plowing > stubbleof wheat > stubble benne. Furthermore, the difference of tillage modes also resulted in differentrelationships between rate of soil deflation (Rd) and wind velocity. Rd of plowing and scrunching isthe largest, and that of stubble of benne is the smallest. The order of Rd for seven tillage modes isas follows: plowing and scrunching > no-stubble > subsoil tillage > stubble of buckwheat >plowing > stubble of wheat > stubble benne. The result of wind tunnel test indicated that theeffects of preventing soil erosion by plowing and scrunching and no-stubble are the poorest, andthose of stubble of benne, stubble of wheat and plowing are the best, and those of subsoil tillageand stubble of buckwheat are placed in the middle.According to the research results, during the course of growth of crop, there are higher soilmoisture content, larger roughness of soil surface and better growth of crop for plowing with stalkmulch and conventional tillage. Furthermore, there is low cost for group one. Plowing with stalkmulch is better than conventional tillage in the growth of crop and preventing wind erosion. Afterharvest time, conventional tillage is the poorest of all the tillage modes for preventing winderosion. For group two, there is high soil moisture content, but the growth of crop and wind statusnear ground is placed in the middle. Ridge tillage not only needs a great deal of surface soil, butalso has high cost. Additionally, for group three, the cost is very low, but soil moisture contents arethe lowest for surface tillage, no-till and subsoil tillage. In period of fallow, high stubble is the bestfor promoting the content of soil moisture and preventing soil erosion by wind.In conclusion, in order to improve soil moisture content, prevent wind erosion and increaseyield of crop, plowing with stalk mulch should be selected in the growth period, and high stubbleshould be selected after the harvest time.In this paper some innovation are listed as follows: soil moisture, crop, near surface windvelocity and soil erosion by wind on farmland were systematically observed and summarized.Accordingly, a useful and feasible technology is put forward for conservation tillage in dryfarmland regions. This technology is benefit not only for increasing yield of crop, but also forpreventing wind erosion.更多还原