【作者】 王笑非；

【导师】 梁卫理；

【作者基本信息】 河北农业大学 ， 作物栽培学与耕作学， 2008， 硕士

【摘要】 河北平原麦田二熟制一方面消耗大量水资源、构成当地农业“不可持续”发展的重要因素，另一方面在保障区域和国家粮食安全方面发挥着重要的作用。从宏观的高度全面地认识这一种植制度，对于科学合理地调整种植业结构具有重要意义。本文运用大样本调查数据和模型方法，对以冬小麦-夏玉米为典型代表的河北平原麦田二熟制和以棉花一熟为代表的一年一熟种植制度的经济效果、水分利用效率和防风蚀效果进行了分析。主要结果如下：（1）利用2004-2005年对河北省曲周县114个农户的调查数据，分析了小麦-玉米和棉花种植的经济效果，结果表明：种植小麦-玉米、棉花的净产值分别为10624．3元／hm²和13870元／hm²，小麦-玉米的净产值比棉田低23．4％；小麦-玉米的盈利为4174．3元／hm²，棉花的盈利为5520元／hm²，小麦-玉米的盈利比棉花低24．4％。（2）运用气象资料和调查数据分析了小麦-玉米和棉花的水分经济利用效率（单位面积单位水资源消耗量的盈利），结果表明：小麦-玉米和棉花的水分经济利用效率分别为4．12元／mm·hm^-2和7．67元／mm·hm^-2，小麦-玉米的水分经济利用效率是棉花的74．46％；小麦-玉米、棉花对灌溉水的经济利用效率分别为11．13／mm·hm^-2和36．80元／mm·hm^-2，小麦-玉米田的灌溉水的经济利用效率是棉花的30．25％。（3）依据EPIC模型的基本原理，建立了一个新的模型用以估算农田风蚀量。该模型的主要参数包括潜在风蚀量、植被覆盖度、土壤可蚀性、地表粗糙度、地块宽度和表层含水量。利用气象数据并使用日平均风速与土壤风蚀量的关系式求出当地农田的潜在风蚀量。根据2m处可蚀风和不同高度风速的关系式得出气象站的临界风蚀速度为6．94m／s。对气象数据分析结果表明，河北平原冬春季节为易蚀性季节，此阶段的可蚀风日数和潜在风蚀量分别占全年的82．35％和68．62％。依据田间实测数据建立了植被覆盖度与作物叶面积指数（LAI）的关系方程，以田间试验条件下的作物LAI数据求得植被覆盖度；依据植被覆盖度与潜在风蚀量的关系方程分析的结果表明：易风蚀季节12月-翌年5月小麦-玉米田比裸露农田减少土壤风蚀量98％，而棉花田在此时无植被覆盖；6-7月和10-11月，小麦-玉米田仅比裸露农田减少土壤风蚀量60％，而棉田可比裸露农田减少土壤风蚀量97％以上。故在易风蚀季节小麦-玉米田防风蚀效应远远大于棉花田。利用土壤剖面含水量与表层含水量的经验公式及根据彭曼公式和农田水分平衡方程计算得出的土壤剖面含水量数据估算土壤表层土壤含水量。结果表明：5月-10月小麦-玉米田和棉田的表层含水量均大于10％，不会发生风蚀；11月-翌年4月小麦-玉米田的表层含水量显著高于棉田，棉花收获后翻耕晒垡使得棉田的表层含水量处于全年最低值，易发生风蚀。因此在易风蚀的冬春季节，小麦-玉米田表层含水量的防风蚀效应大于棉田。用与农田初始粗糙度(Z_^*0)相对应的土壤风蚀量对地表粗糙度（Z₀）与土壤风蚀量的关系方程进行修正。利用Z₀与土壤粒径之间的定量关系计算农田初始粗糙度(Z_^*0)的值，并根据不同耕作措施之间地表粗糙度的定量关系，估算出不同耕作措施的Z₀的值。研究结果表明：Z₀及其防风蚀效果与耕作措施呈正显著相关关系。秸秆覆盖的小麦-玉米田和不拔柴的棉田的地表粗糙度最大，Z₀为22．1cm和19．32cm，FR为0，防风蚀效果最好；其次为免耕农田，Z₀值为13cm，FR为0；常规耕作小麦-玉米田（秸秆还田）和棉田（覆膜+翻耕）的Z₀为0．52cm和0．58cm，FR为26％和25％，比裸露农田的土壤风蚀量减少74和75％；传统旋耕小麦-玉米田和棉田的Z₀为0．45cm，比裸露农田的土壤风蚀量减少65％。利用两个地点的试验数据对新建立的土壤风蚀模型进行了验证，结果表明，新建立的土壤风蚀模型的模拟值与实测值的线性吻合程度较好，达到5％统计显著水平。（4）运用新建立的风蚀模型估算农田风蚀量的结果表明：小麦-玉米田的土壤风蚀量为100．7 kg／hm²，棉田的土壤风蚀量为1603．6kg／hm²，小麦-玉米田的风蚀量仅为棉田的6．2％；小麦-玉米田和棉田因土壤风蚀造成的经济损失分别为0．77元／hm²和12．21元／hm²，小麦-玉米田比棉田减少风蚀损失11．44元／hm²。综上所述，河北平原小麦-玉米田的单位面积净产值、盈利和水分经济利用效率均低于棉田，但防风蚀效果远远高于棉田。更多还原

【Abstract】 On the one side, wheat-based double cropping system in hebei plain cost mass water resource, which was the key factor of "non-sustainable" developing agriculture. On the other side, it plays an important role in the protection of regional and national food security. Understanding the croping system all-around from macroscopical point is of great significance to adjust crop structure scientificly and reasonably. In this paper, using a large sample survey data and model, we analysised the economic efficiency and water economic use effeciency use economic efficiency and erosion-preventing effects of wheat-maize and cotton fields in hebei plain. The result shows:（1） The economic effects of wheat -maize and cotton fields were analyzed using the investigating data from 114 farmers in quzhou county during the year 2004-2005, the rusults showed: the net output of wheat-maize and cotton fields were separetely 10624.3 yuan/hm² and 13870 yuan/hm², the net output of wheat-maize and cotton fields were separetely 4174.3 yuan/hm² and 5520 yuan/hm², the net prifits in wheat -maize was lower 24.4% than that of cotton.（2） Water economic use efficiency （the profit of water consumption per unit area） was analyzed using meteorologic and survey data. The results showed: Water economic use effeciency of wheat -maize and cotton field were separetely 4.12 yuan/ mm·hm^-2 and 7.67 yuan/ mm·hm^-2. Water economic use effeciency of wheat -maize was 74.46% of that of cotton. The irrigation water economic use effeciency of wheat -maize and cotton field were separetely 11.13 yuan/ mm·hm^-2 and 36.80 yuan/ mm·hm^-2. The irrigation water economic use effeciency of wheat -maize was 30.25% of that of cotton.（3） We established a new modle on the basis of EPIC model to estimates the amount of wind erosion on farmland. The main parameters of the model included the amount of potential wind erosion, vegetation cover, soil erodibility, surface roughness, block width and surface soil moisture.Using meteorologic data and the relationship between the average wind speed and amount of wind erosion, we estimated the amount of potential wind erosion. And using the value on eroding wind of 2m hight and the relationship among different high-speeds, we calculated the value of eroding wind of meteorological station, 6.94m/s. The result of analysising meteorological data showed, the days of eroding wind in winter-spring season was 82.35% of that of the annual volume, and the amount of potential wind erosion in winter-spring season was 68.62% of that of the annual volume.We estimated the value of vegetation using the LAI obtained from the field experiment and the relationship equation between vegetation cover and the crops leaf area index; and then we calculated the amount of wind erosion by the relationship equation between vegetation cover and the the amount of wind erosion; The result showed: the amount of wind erosion rised by planting wheat-maize was 2% of that of bare farmland, but the amount of wind erosion by planting cotton in winter-spring season was 100% of that of bare farmland, the amount of wind erosion rised by planting wheat-maize was 40% of that of bare farmland from June to July and from October to November, but the amount of wind erosion rised by planting cotton was 3% of that of bare farmland. Therefore, the erosion-preventing effect of wheat-maize was better than that of cotton fields.We estimated surface soil moisture the relationship equation between surface soil moisture and profile soil moisture calculated penman formula and farmland water balance equation. The resulted showed: the amount of wind erosion rised by planting wheat-maize and cotton was merely 0, because the surface soil water of wheat-maize and cotton fields was more than 10%. And the amount of wind erosion rised by planting wheat-maize was larger than that of cotton fields from November to next year April, because surface soil moisture of cotton fields was in the annual minimum value. Therefore, the erosion-preventing effect of wheat-maize was better than that of cotton fields.We revised the ralathionship equation between land surface roughness and the amount of wind erosion according to the value of the amount of wind amount of wind erosion correspond to initial land surface roughness. And then we calculated the value of the amount of wind erosion by the value of land surface roughness estimated by the relationship between land surface roughness （Z₀） and the diameter of soil particles and the ralationship of different tillage. The result showed: the land surface roughness of wheat-maize fields with straw stalk cover and the cotton fields with firewood was the biggest, Z₀ was 22.1cm and 19.32cm, FR was 0, the erosion-preventing effects was the biggest; the no-tillage wheat-maize and cotton fields was next, Z₀ was 13cm, FR was 0; And then it was conventional cultivation wheat-maize fields （straw stalk also field） and cotton fields （rotary + ploughing）, Z₀ was 0.52cm and 0.58cm, FR was 26% and 25%, it was planting wheat-maize and cotton that reduced 76 and 76% of the amount of wind erosion compared to bare farmland. Z₀ of traditional rotary cultivation wheat maize and cotton fields was 0.45cm, which could reduces 65% of amount of wind erosion compared to bare farmland.We tested the new modle with the experimental data of two different places. The result showed: the effect of the new modle was good, which achieved 5% remarkable level.（4） We estimated the amount of wind erosion by the new modle, the result was that the amount of wheat-maize fields was 100.7 kg/hm², and that the amount of cotton fields was 1603.6 kg/hm². the value on the amount of wheat-maize fields was 6.2% of the value on the amount of cotton fields. Moreover, the economic loss rised by soil nutrient outflow of wheat- maize fields was 0.77 Yuan /hm². and the economic loss rised by soil nutrient outflow of cotton fields was 12.21 Yuan /hm².In summary, in Hebei plain, the wheat - maize field’s net output value of unit area,the profit and the water economic use efficiency were lower than that of the cotton field, but wind erosion-resisitence effect is higher than that of the cotton field by far.更多还原