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1.
Assessment of tillage translocation and tillage erosion by hoeing on the steep land in hilly areas of Sichuan, China 总被引：9，自引：0，他引：9
Most of the tillage erosion studies have focused on the effect of tractor-plough tillage on soil translocation and soil loss. Only recently, have a few studies contributed to the understanding of tillage erosion by manual tillage. Furthermore, little is known about the impact of tillage erosion in hilly areas of the humid sub-tropics. This study on tillage erosion by hoeing was conducted on a purple soil (Regosols) of the steep land, in Jianyang County, Sichuan Province, southwestern China (30°24′N and 104°35′E) using the physical tracer method.
The effects of hoeing tillage on soil translocation on hillslopes are quite evident. The tillage transport coefficients were 26–38 kg m−1 per tillage pass and 121–175 kg m−1 per tillage pass respectively for k3- and k4-values. Given that there was a typical downslope parcel length of 15 m and two times of tillage per year in this area, the tillage erosion rates on the 4–43% hillslopes reached 48–151 Mg ha−1 per year. The downslope soil translocation is closely related to slope gradient. Lateral soil translocation by such tillage is also obvious though it is lower than downslope soil translocation. Strong downslope translocation accounts for thin soil layers and the exposure of parent materials/rocks at the ridge tops and on convexities in the hilly areas. Deterioration in soil quality and therefore reduction in plant productivity due to tillage-induced erosion would be evident at the ridge tops and convex shoulders. 相似文献
2.
Large amounts of soil are eroded annually from tilled, hilly upland soils in the humid tropics. Awareness has been increasing that much of this erosion may be due to tillage operations rather than water-induced soil movement. This field study estimated soil translocation and tillage erosion for four tillage systems on Oxisols with slope gradients of 16–22% at Claveria, Misamis Oriental, Philippines. Soil movement was estimated using ‘soil movement tracers' (SMT) which consisted of painted 12-mm hexagonal steel nuts. The SMT were buried in three replicate plots of the following tillage treatments: (1) contour moldboard plowing in the open field (MP-open); (2) contour ridge tillage in the open field (RT-open); (3) contour moldboard plowing plus contour natural grass barrier strips (MP-strip); and (4) contour natural grass barrier strips plus ridge tillage (RT-strip). Two hundred SMT were placed at the 5-cm depth at 5-cm spacings on 10 rows and 20 columns in two microplots within each plot. The microplots were oriented with the boundaries running downslope and along the contour of each 8-m-wide × 38-m-long (downslope) tillage plot. After tilling the land for four successive corn (Zea mays L.) crops (20 tillage operations), the SMT were manually excavated and their positions recorded. Recovery of SMT ranged from 82% to 85%. Displacement of SMT was directly related to slope length, percent slope, and tillage method. Mean displacement distance of SMT during the four corn growing seasons was 3.3 m for MP-open, 1.8 m for RT-open, 1.5 m for the RT-strip, and 2.2 m for MP-strip. Based on tillage operations associated with two corn crops per year, mean annual soil flux was estimated to be 241, 131, 158 and 112 kg m−1 for MP-open, RT-open MP-strip, and RT-strip, respectively. Compared to the mean annual soil loss for MP-open of 63 Mg ha−1, soil loss was reduced by 30%, 45%, and 53% for the MP-strip, RT-open, and RT-strip systems, respectively. Both ridge tillage and natural grass barrier strips reduced soil displacement, soil translocation flux, and tillage erosion rates. 相似文献
3.
Soil translocation by tillage may be an important factor in land degradation in the humid tropics. The objective of this study was to evaluate tillage-induced soil translocation on an Oxisol with 25% and 36% slopes in Claveria, Philippines for three tillage systems: contour moldboard plowing (CMP), moldboard plowing up and downslope (UMP), and contour ridge tillage (CRT). Small rocks 3–4 cm in “diameter” were used as soil movement detection units (SMDU). The SMDUs were placed at 10 cm intervals in a narrow 5-cm-deep trench near the upper boundary of each plot, the position of each rock recorded, and the trench backfilled. Five tillage operations used to produce one corn crop were performed during a one month period: two moldboard plowing operations for land preparation (except for CRT), one moldboard plowing for corn planting, and two inter-culture (inter-row cultivation) operations. After these operations, over 95% of the SMDU were recovered manually and their exact locations recorded. Mean annual soil flux for the 25% slope was 365 and 306 kg m−1 y−1 for UMP and CMP, respectively. For the 36% slope, comparable values were 481 and 478 kg m−1 y−1. Estimated tillage erosion rates for the 25% slope were 456 and 382 Mg ha−1 y−1 for UMP and CMP, respectively, and increased to 601 and 598 Mg ha−1 y−1, respectively, for the 36% slope. The mean displacement distance, mean annual soil flux, and mean annual tillage-induced soil loss for both slopes were reduced by approximately 70% using CRT compared to CMP and UMP. 相似文献
4.
Abstract. Current tillage erosion models account for the influence of tillage direction in the magnitude of the soil (tillage) transport coefficient. It is argued here that this is counter-intuitive and causes significant problems in modelling tillage erosion in areas of complex terrain. This article examines whether a re-modelling of tillage erosion is possible that separates tillage direction (an interaction with the landform) from the soil transport coefficient (a measure of tillage intensity representing the combination of implement erosivity and soil erodibility). Experimental data for mouldboard ploughing upslope, downslope and cross-slope at Coombe Barton Farm, Devon are examined. Integration of data for all directions into a single relationship, which relates translocation in the direction of tillage to slope in the direction of tillage and translocation perpendicular to tillage to slope perpendicular to tillage, is not possible using previously published methods of analysis. However, when total translocation distance is regressed against the tangent of the slope at 45° to the tillage direction (bisecting the tillage direction and the direction of overturning) it is found that a single relationship can be used to describe tillage in all three directions. Therefore, this relationship is used to determine a single value of the soil transport coefficient ( k fTa ) for constant soil and implement conditions but different tillage directions. This redefinition of tillage is important both for true estimation of tillage erosion severity, the adirectional coefficient being 40% larger than the directional coefficient, and for modelling of tillage erosion in complex terrain. These improvements are vital when tillage erosion simulation is used to direct soil conservation strategies. 相似文献
5.
东北黑土区典型坡面耕作侵蚀定量分析 总被引：2，自引：1，他引：2
东北黑土区水土流失主要集中在坡耕地,以往研究多关注水蚀而忽略了耕作侵蚀的存在。为印证并定量描述黑土耕作侵蚀,该文采用物理示踪法,测定了典型坡耕地耕作位移量及其分布格局。结果表明:铧式犁耕作后示踪剂沿耕作方向发生扩散,上坡耕作示踪剂集中分布在0~20 cm范围,而下坡耕作示踪剂集中分布在0~20和50~150 cm。一次耕作引起的耕作位移量为32.68~134.14 kg/m,耕作迁移系数234 kg/m。坡度是影响耕作位移的重要因素,二者呈显著的正相关关系,且对上坡耕作的影响大于下坡耕作。研究区耕作年侵蚀速率0.4~11.0 Mg/(hm2·a),凸起的坡背、坡肩处及坡度较大的位置侵蚀严重。虽然黑土区坡度较小,但由于耕作深度大,速度快,耕作侵蚀严重,应引起足够重视。 相似文献
6.
岩溶区坡地耕作侵蚀过程中的土壤再分布研究 总被引：4，自引：1，他引：4
对耕作侵蚀引起的土壤空间再分布进行研究,有利于改革不合理的耕作方式和治理坡耕地水土流失。本文以重庆市中梁山为例用示踪法对坡耕地进行试验研究。结果表明:随着坡度的增大,耕作后示踪剂在示踪区的含量越来越少;它的最大值出现的位置离基线越来越远,值越来越小;沿耕作方向移动的距离越来越远。这种规律性以锄头和铁锹顺坡明显,等高和踩锹顺坡不明显。从本区耕作侵蚀的角度考虑,等高耕作方式明显要优于顺坡耕作;在顺坡耕作中踩锹优于锄头和铁锹。最后还结合岩溶山区特殊的自然环境条件,讨论了耕作侵蚀对石漠化的影响。 相似文献
7.
Tillage erosion studies have mainly focused on the effect of topography and cultivation practices on soil translocation during tillage. However, the possible effect of initial soil conditions on soil displacement and soil erosion during tillage have not been considered. This study aims at investigating the effect of the initial soil conditions on net soil displacement and the associated erosion rates by a given tillage operation of a stony loam soil. Tillage erosion experiments were carried out with a mouldboard plough on a freshly ploughed (pre-tilled) soil and a soil under grass fallow in the Alentejo region (Southern Portugal).
The experimental results show that both the downslope displacement of soil material and the rate of increase of the downslope displacement with slope gradient are greater when the soil is initially in a loose condition. This was attributed to: (i) a greater tillage depth on the pre-tilled soil and (ii) a reduced internal cohesion of the pre-tilled soil, allowing clods to roll and/or slide down the plough furrow after being overturned by the mouldboard plough.
An analysis of additional available data on soil translocation by mouldboard tillage showed that downslope displacement distances were only significantly related to the slope gradient when tillage is carried out in the downslope direction. When tillage is carried out in the upslope direction, the effect of slope gradient on upslope displacement distances was not significant. This has important implications for the estimation of the tillage transport coefficient, which is a measure for the intensity of tillage erosion, from experimental data. For our experiments, estimated values of the tillage transport coefficient were 70 and 254 kg m−1 per tillage operation for grass fallow and pre-tilled conditions, respectively, corresponding to local maximum erosion rates of ca. 8 and 35 Mg ha−1 per tillage operation and local maximum deposition rates of ca. 33 and 109 Mg ha−1 per tillage operation. 相似文献
8.
Few studies have demonstrated soil redistribution under upslope tillage (UT) rather than downslope tillage (DT) and its impact on soil organic carbon (SOC) redistribution in long‐term agricultural practices in hillslope landscapes. We selected two neighbouring sites from the Sichuan Basin, China, one under DT and the other under UT, to determine the pattern of soil and SOC redistribution under a long‐term UT practice. DT caused soil loss at upper slope positions and soil accumulation at lower slope positions. However, UT resulted in soil accumulation at upper slope positions and soil loss at lower slope positions. The total erosion rate decreased by 60.5% after 29 years of UT compared with DT. Having the same direction of soil movement by tillage and water exaggerated total soil loss, whereas having the two movements in the contrasting direction of soil for the two reduced it. SOC stocks at positions from summit to downslope were much larger (33.8%) and at toe‐slope positions were only slightly greater (4.5%) in the UT soils than comparable values for the DT site. The accumulation rate of SOC at the UT site increased by 0.26 Mg/ha/year compared with that at the DT site. It is suggested that soil movement by water and tillage erosion occurred in the same direction accelerates the depletion of SOC pools, whereas the opposite direction of soil movement for the two can increase SOC accumulation. Our results suggest that UT has significant impacts on soil redistribution processes and SOC accumulation on steeply sloping land. 相似文献
9.
S. De Alba L. Borselli D. Torri S. Pellegrini P. Bazzoffi 《Soil & Tillage Research》2006,85(1-2):123-142
This study was designed to characterise the soil translocation effect induced by mouldboard ploughing with an implement traditionally used in the Tuscany region (Central Italy). We discuss the results of a set of field experiments performed to measure soil displacement along slopes of varying gradient in different directions and at several depths of tillage. Using the Soil Erosion by Tillage (SETi) model, soil translocation patterns for different tillage scenarios were analysed, with special attention paid to the effects of the direction and depth of tillage on the extent and spatial pattern of soil movement. The lateral slope gradient SP and tillage depth D were found to be the dominant controlling factors for total soil displacement. The effect of the slope gradient in a direction parallel to tillage ST was much less pronounced. These findings reveal the importance of the asymmetric nature of the soil movement produced by mouldboard ploughing and the predominant effect of the lateral displacement dP on the actual trajectory of soil motion. Results demonstrate that spatial patterns of soil redistribution due to mouldboard ploughing are highly variable and depend on the particular characteristics of the implement used. This dependence is so strong that maximum downslope soil translocation can occur during both, contour tillage or up–down tillage. For this particular mouldboard plough, maximum downslope soil transport took place at a tillage direction ca. 70° and not when tillage was conducted along the steepest slope direction (0°). These findings highlight the potential of the combined approach applied. The physically based SETi model can be properly calibrated using a relatively limited dataset from field experiments. Once calibrating, the SETi model can then be used to generate synthetic tillage translocation relationships, which can predict the intensity and spatial pattern of soil translocation over a much wider range of tillage scenarios than the particular experimental conditions, in terms of topography complexity (slope gradients and morphology) and the direction and depth of tillage. These synthetic relationships are useful tools for evaluating strategies designed to reduce tillage erosion. 相似文献
10.
黑土区垄作方式对坡耕地土壤侵蚀的调控效果 总被引：1，自引：0，他引：1
[目的]分析黑土区不同垄作方式对坡耕地土壤侵蚀的调控效果,为该区土壤侵蚀防治提供科学指导。[方法]在5°和10°坡耕地开展人工模拟降雨试验,降雨强度为50,100 mm/h,垄作方式包括：横坡垄作、垄向区田、顺垄+底部横垄和横垄+排水沟,对照处理为传统顺坡垄作。[结果]试验条件下,与顺坡垄作处理相比,横坡垄作、垄向区田、顺垄+底部横垄和横垄+排水沟处理均可有效调节径流、降低土壤侵蚀量,但不同垄作方式对径流和侵蚀的调控效果随着降雨强度和坡度的增加而减小。在5°坡耕地,横坡垄作方式对径流和侵蚀的调控效果最佳,产流率和土壤侵蚀速率分别稳定在15.0 mm/h和0.2 kg/(m~2·h)以下。在50,100 mm/h降雨强度下,与顺坡垄作处理相比,其径流量分别降低92.3%和83.9%,土壤侵蚀量分别降低96.8%和94.6%;而垄向区田方式对径流和侵蚀的调控效果略大于顺垄+底部横垄处理。在10°坡耕地,横坡垄作方式在降雨前期具有较好的蓄水保土作用,但在降雨后期垄体易损坏,造成土壤侵蚀量剧增;横垄+排水沟方式在降雨前期能够蓄水保土,在降雨后期能够较好地进行排水。[结论]在坡度平缓的坡耕地,应... 相似文献
11.
J. A. Montgomery D. K. McCool A. J. Busacca B. E. Frazier 《Soil & Tillage Research》1999,51(3-4):175-187
Most of the erosion research in the Palouse region of eastern Washington State, USA has focused on quantifying the rates and patterns of water erosion for purposes of conservation planing. Tillage translocation, however, has largely been overlooked as a significant geomorphic process on Palouse hillslopes. Tillage translocation and tillage deposition together have resulted in severe soil degradation in many steep croplands of the Palouse region. Few controlled experiments have heretofore been conducted to model these important geomorphic processes on Palouse hillslopes. The overarching purpose of this investigation, therefore, was to model tillage translocation and deposition due to moldboard plowing in the Palouse region. Soil movement by moldboard plowing was measured using 480-steel flat washers. Washers were buried in silt loam soils on convex–convex shoulder, linear-convex backslope, and linear-concave footslope landform components, and then displaced from their original burial locations by a moldboard plow pulled by a wheel tractor traveling parallel to the contour at ca. 1.0 m s−1. Displaced washers were located using a metal detector, and the distance and azimuth of the resultant displacement of each washer from its original burial location was measured using compass and tape. Resultant displacement distances were then resolved into their component vectors of displacement parallel and perpendicular to the contour. A linear regression equation was developed expressing mean soil displacement distance as a function of slope gradient. Tillage translocation and deposition were modeled as diffusion-type geomorphic processes, and their rates were described in terms of the diffusion constant (k). A multivariate statistical model was developed expressing mean soil displacement distance as a function of gravimetric moisture content, soil bulk density, slope gradient, and direction of furrow slice displacement. Analysis of variance (ANOVA) revealed a weak correlation between soil displacement and both bulk density and moisture content. Soil displacement was, however, significantly correlated with direction of furrow slice displacement. Tillage translocation rates were expressed in terms of the diffusion constant (k) and ranged from 105 to 113 kg m−1 per tillage operation. Tillage deposition rates ranged from 54 to 148 kg m−1 per tillage operation. With respect to tillage deposition, the diffusion constant calculated from volumetric measurements of tillage deposits equals ca. 150 kg/m. The rates of tillage translocation and deposition are not completely in balance; however, these rates do suggest that soil tillage is a significant geomorphic process on Palouse hillslopes and could account for the some of the variations in soil physical properties and crop yield potential at the hillslope and farm-field scale in the Palouse region. 相似文献
12.
Simulation and 137Cs tracer show tillage erosion translocating soil organic carbon,phosphorus, and potassium 总被引：1，自引：0，他引：1
Research on how tillage‐induced soil redistribution affects soil properties is limited for complex slopes in nonmechanized agricultural areas. The objectives of this study are (1) to examine the vertical redistribution of soil organic C (SOC), extractable P and K induced by tillage on a complex slope, (2) to assess the effects of tillage erosion on soil profile properties, and (3) to elucidate the variations in soil properties induced by both vertical mixture and downslope transport of soil within the landscape. Simulated tillage was conducted in the Yangtze Three Gorges Reservoir Area, China. The 137Cs data showed that intense tillage caused the soil vertical mixture and downslope transport. The redistribution of 137Cs and soil constituents varied with the number of tillage passes and location in relation to curvature. SOC was completely depleted with the disappearance of soil profiles at the summit position, while SOC concentrations decreased by 26% for the till layer and increased by 29% for the sublayer at the toeslope position for the 15‐tillage operation, as compared with those of pretillage. The vertical redistribution of extractable P and K followed a similar pattern to that of SOC. The gap and variation in soil constituents between the till layer and sublayer declined after tillage, suggesting that the mixing effect of tillage attenuates the variability of soil properties in the vertical direction. Net loss and gain of soil constituents occurred at the summit and toeslope positions, respectively, suggesting that the downslope transport of soil induced by tillage accentuates the variability of soil properties in the lateral direction. 相似文献
13.
Changing land-use practices in northern Thailand have increased tillage intensity. This study re-assesses the rate of tillage erosion by manual hoeing on steep slopes (17–82%) in northern Thailand. Previously collected soil translocation data during an on-farm tillage erosion experiment and additionally collected data during an on-farm tillage erosion survey have been analysed whereby a new calculation method (i.e. trapezoid tillage step) has been used. A comparison with previously collected data indicates that the trapezoid tillage step method and the tracer method are the most reliable methods to assess downslope translocation by manual tillage. Based on newly acquired understanding of the processes involved, soil fluxes by tillage erosion are quantified by linear functions for different slope gradient classes rather than one single diffusion-type equation for the whole slope range. For slope gradients smaller than 3%, soil fluxes are close to zero as farmers do not have a preferred tillage direction. For slope gradients between 3% and 70%, soil is tilled only in the downslope direction and soil fluxes range between 16 and 67 kg m−1 tillage pass−1. On slopes with gradients in excess of 70%, the angle of repose for soil clods is often exceeded resulting in a sliding down of the complete tilled top layer. These data are used to assess the soil flux for complete cropping cycles for the most dominant cropping systems in the highlands of northern Thailand: i.e. upland rice, maize, (soy) beans, cabbage and ginger. The on-site effects of tillage erosion will be very pronounced if parcels are short with respect to their slope length, cultivated for upland rice or cabbage, or when weed pressure is high. Tillage erosion results in a tillage step with low soil fertility and low infiltration capacity. Solutions to reduce tillage erosion intensity depend on the degree that tillage intensity can be reduced. This might happen by an improved weed management or by changing landuse to perrenial cropping. Other strategies are concentrating nutrients on the truncated hillslope sections and retaining soil on the field by vegetative buffers. 相似文献
14.
耕作侵蚀及其对土壤肥力和作物产量的影响研究进展 总被引：3，自引：1，他引：2
在坡耕地景观内,由于农耕工具和重力作用而引起的耕作位移使土壤发生向下坡运动或向上坡运动(依赖于耕作方向),导致净余土壤量向下坡传输、堆积,重新分配,从而形成耕作侵蚀。试验研究表明耕作侵蚀是坡耕地的主要侵蚀形式之一,耕作侵蚀发生最严重的区域是坡度较大、坡体短的坡耕地。该文就耕作侵蚀的概念、发生机理、典型的耕作侵蚀模型的发展,以及耕作侵蚀对土壤肥力和作物产量影响的研究现状作了简要论述,特别总结了针对中国的地貌和耕作工具特征而进行的耕作侵蚀的研究成果。指出在一定的景观范围内,耕作侵蚀是十分严重的,甚至其严重程度已经超过了水蚀。但是相对于水蚀而言,耕作侵蚀研究还很少,因此加强耕作侵蚀的研究是十分必要的。只有这样才能正确评价农耕地侵蚀状况,准确制定土壤保持措施和采用减少耕作侵蚀力的耕作工具,从而有效地控制土壤侵蚀。 相似文献
15.
东北黑土区不同垄向耕地沟蚀与地形耦合规律 总被引：6，自引：2，他引：4
东北黑土区在长期高强度开垦连作下,侵蚀沟切割耕地地表现象严重。以黑龙江省宾县的两个典型乡镇为研究区,基于GIS和RS技术,采用全局空间自相关、样方网格等方法,综合垄向、侵蚀沟、地形数据探究区域尺度下垄向分布及不同垄向耕地沟蚀与地形因子耦合规律。结果表明:（1）不同乡镇沟蚀空间集聚程度不同,主导性垄向耕地内的侵蚀程度最高;（2）垄向在耕地上的分布有很强的空间自相关性,不同的垄向空间分布是对地形条件的反馈体现,合理的垄向空间分布会起到降低沟蚀密度的作用;（3）除糖坊镇斜垄外,不同垄向耕地沟蚀密度随海拔的升高呈现先增大后减小的趋势。糖坊镇不同海拔级优势垄向规律性不强,三宝乡整体上任意海拔级斜垄耕作最优;（4）坡度与坡长交互作用显著。两乡镇表现为“小坡度”+“小坡长”或“小坡度”+“大坡长”条件横垄耕作最优,“大坡度”+“小坡长”或“大坡度”+“大坡长”条件斜垄耕作最优;（5）黑土区漫川漫岗地带斜垄耕作更具水土保持作用。 相似文献
16.
东北黑土区在中国粮食安全与可持续发展中占据重要地位,但过度开发利用导致该区土壤侵蚀问题严峻。耕作方式的差异直接影响黑土区坡耕地土壤侵蚀特征,相关研究的开展对于准确评价水土保持措施的适宜性具有重要意义。该研究通过系统梳理文献资料,总结了垄向、垄规格以及垄向区田技术的内涵及应用条件,分别综述了其对黑土区坡耕地土壤侵蚀的影响;指出了目前研究中还存在垄作与垄向区田技术对坡耕地土壤侵蚀影响的机理研究不深、垄向与垄规格之间的耦合关系分析不细、垄向区田垄沟土埂优化设计不足、土壤侵蚀综合影响因素探索不全等方面主要问题;明确了未来研究中应加强量化垄向、垄规格、垄向区田技术与其他水土保持措施相结合对黑土区坡耕地土壤侵蚀影响的过程与机理,为筛选适宜的水土保持耕作措施提供科学依据。 相似文献
17.
18.
四川黄壤区玉米季坡耕地自然降雨及其侵蚀产沙特征分析 总被引：6，自引：4，他引：2
为明确玉米全生育期自然降雨特征以及坡耕地产流产沙规律,以研究区自然降雨为基础,采用野外径流小区和室内分析相结合的方法,分别对横坡垄作、平作和顺坡垄作坡面玉米全生育期(苗期、拔节期、抽雄期和成熟期)的自然降雨、径流及侵蚀产沙量进行了测定。结果表明:研究区2015年玉米全生育期内雨量为676.71mm,其中成熟期侵蚀性雨量达411.71mm,占累计侵蚀性雨量的69.85%。玉米全生育期内,产流受雨量、玉米生育期显著影响,横坡垄作产沙受雨量、雨强的影响显著,而平作和顺坡垄作则受雨量、株高的影响显著;产流产沙均随玉米生育期的推进逐渐增加,且产沙受产流影响显著,横坡垄作和平作含沙量先减小后增加再减小,而顺坡垄作则先减小后增加;抽雄期横坡垄作产流显著小于顺坡垄作而产沙显著小于平作和顺坡垄作,成熟期横坡垄作产流产沙显著小于平作和顺坡垄作。研究区自然降雨条件下,雨量是影响黄壤坡耕地产流产沙的最主要因子,产沙滞后于产流;玉米成熟期土壤侵蚀最为严重,横坡垄作是防治研究区水土流失的有效途径,研究成果为山地黄壤水土流失有效防控与农业的可持续发展提供理论参考。 相似文献
19.
不同耕作措施对黑土坡耕地土壤侵蚀的影响 总被引：12，自引：0，他引：12
针对黑龙江省西部半干旱区土壤流失情况,在坡耕地径流小区通过野外人工模拟降雨试验,研究不同降雨强度、不同耕作措施下降雨产沙产流特征和过程。试验结果表明:降雨强度越大,对地表径流量和侵蚀量的影响越大,即雨强与径流量和泥沙量呈正相关,各种耕作措施的土壤流失顺序是顺坡垄裸地>横坡垄裸地>等高种植地>深松地>秸杆覆盖地>垄向区田地,植被覆盖地能有效控制水土流失,垄向区田地是这几种耕作措施中减少坡耕地水土流失的有效措施。 相似文献
20.
《Communications in Soil Science and Plant Analysis》2012,43(5-6):421-441
Abstract The use of conservation tillage methods, including ridge tillage, has increased dramatically in recent years. At the present time, there is great concern that farmers are applying more nitrogen (N) fertilizer than is environmentally or economically sound. In order to determine if N requirement for optimum yield differs with tillage system, tests were initiated to study tillage and N effects on N content, soil moisture content, and yield of corn (Zea mays L.). The study was established in 1987 on two soil types, an Estelline soil (Pachic Haploboroll) and an Egan soil (Udic Haplustoll), located in eastern South Dakota. Five rates of N (0, 65, 130, 195, and 260 kg ha?1) were applied to plots managed with 3 tillage systems: chisel plow, moldboard plow, and ridge. On the Estelline soil, in both 1988 and 1989, ridge‐tilled plots contained a greater amount of water in the soil profile at emergence and at mid silk than did plots in the other two tillage systems. Soil moisture content at mid silk was significantly correlated with earleaf N, total N uptake, and grain yield in 1988 and earleaf N and grain yield in 1989. However, the correlation coefficients were higher in 1988 than in 1989. On the Egan soil, there were no significant differences in soil moisture content among tillage systems. On the Estelline soil, corn grain yield was affected by a tillage x N‐rate interaction in 1988. Maximum yield within the ridge system was achieved with the 130 kg ha?1 rate. In 1989 on the Estelline soil, yield was affected by tillage and N rate, but there was no interaction between factors. When averaged over N rates, yields were 7.1, 6.6, and 6.5 Mg ha?1 in the ridge, moldboard, and chisel systems, respectively. In 1988 plant total N uptake was greater in the ridge system than the moldboard or chisel systems; in 1989 uptake was affected by N rate alone. On the Egan soil, tillage did not affect soil moisture, total N uptake or grain yield in either year. Corn grain yield increased with increasing N rate up to the 195 kg ha?1 rate. This study indicates that, on some soil types, ridge tillage can improve soil water holding capacity, N utilization and yield of corn. 相似文献