Spatial analysis of long‐term effects of different tillage practices based on penetration resistance

Measuring penetration resistance (PR) is a common technique for evaluating the effects of field management on soils. This study focuses on the effects of long‐term tillage on the spatial distribution of PR, comparing reduced and conventional tillage (CT) practices. The study site, located in Lower Saxony (Germany), has been subdivided into three plots, with one plot having been managed conventionally, whereas reduced tillage (RT) practices have been applied to the other two. In total, PR was measured at 63 randomly selected points. The PR data were stepwise interpolated using kriging with external drift. Core samples have been taken at 20 additional sites. The results show significant differences in PR between the different tillage practices. Within the conventionally managed plot, PR ranges to 2.3 MPa less in the topsoil than under RT. However, measured saturated hydraulic conductivity and amount of biopores at the depth of 30–35 cm are significantly greater under RT, indicating improved soil properties under RT. Comparisons between the headlands (HL) and the inner field point out the effects of intense field traffic in the HL, where maximum PR values of about 6 MPa have been measured. The spatial prediction of PR values show that long‐term effects of different tillage practices result in clearly structured patterns between CT and RT and the HL. Combining extensive PR measurements and point measurements of additional soil properties supports an adequate interpretation of PR data and can lead to fieldwide derivation of soil functions influenced by field management.     

Tillage effects on the accumulation of polychlorinated biphenyls in biosolid‐amended soils

Soil tillage along with the application of organic waste probably affects the concentrations of organic carbon and the enrichment of introduced polychlorinated biphenyls (PCBs). In a three‐year experiment the PCB status of soils from three different field sites (silty clay loam, silt loam, sandy loam) which were long‐term differently tilled (NT = no‐tillage, CT = conventional plough tillage) and amended with two different organic wastes such as sewage sludge and compost (biosolids) was examined. No significant alteration in soil‐PCB quality and quantity with biosolid application could be proven within the course of the experiments. This indicates soil‐air exchange of PCBs dominates their concentrations in soil. Organic carbon in soil was significantly tillage‐dependent and determined the fate of PCBs resulting in a generally elevated PCB‐level in the non tilled soils. Linear regression of PCB load and organic matter content of all investigated untreated soils was highly significant (R² = 0.73). Due to already elevated PCB levels in non tilled soils with a maximum of 65 μg kg^—1 in the superficial layer of the silt loam control plot, any additional potential input, i. e. through the amendment with organic wastes, should therefore be avoided.     

Effect of tillage intensity on weed infestation in organic farming

Conservation tillage is not yet widely accepted by organic farmers because inversion tillage is considered to be necessary for weed control. Three long-term experiments were established with combinations of reduced and conventional plough tillage and stubble tillage to determine weed infestation levels in organic farming, i.e. herbicide application being excluded. Experiment 1 (with very low stocking density of perennial weeds) showed that in presence of primary tillage by mouldboard ploughing the number of annual weeds was nearly unaffected by the mode of stubble tillage. In experiment 2, however, with Canada thistle (Cirsium arvense) being artificially established, thistle density was significantly affected by stubble tillage and by a perennial grass–clover forage crop. Experiment 3 combined two levels of stubble tillage (skimmer plough, no stubble tillage = control) with four implements of primary tillage in the order of decreasing operation depth (deep mouldboard plough, double-layer plough, shallow mouldboard plough or chisel plough). Primary tillage by chisel plough resulted in significantly highest annual weed density compared to all other treatments. The natural C. arvense infestation in experiment 3 showed highest shoot density in the “skimmer plough/chisel plough” treatment compared to the lowest infestation in the “skimmer plough/double-layer plough” treatment. The poor capacity of the chisel plough for weed control was also reflected by the soil seed bank (5500 m⁻² C. arvense seeds for chisel plough, <300 seeds for all other primary tillage). A reduced operation depth of the mouldboard plough (“shallow mouldboard plough”) seemed to have an insufficient effect in controlling C. arvense infestation as well. Stubble tillage by the skimmer plough in addition to nearly any primary tillage operation largely reduced both annual weeds and thistle shoots. Most effective in controlling C. arvense was also a biennial grass–clover mixture as part of the crop rotation.Double-layer ploughing is a compromise between soil inversion and soil loosening/cutting and can be regarded as a step towards conservation tillage. In terms of controlling annual weeds and C. arvense, the double-layer plough was not inferior to a deep mouldboard plough and seems to be suitable for weed control in organic farming. Tilling the stubble shallowly after harvest can support weed control in organic farming remarkably, particularly in reducing C. arvense. If no noxious, perennial weeds occur and primary tillage is done by soil inversion, an omission of stubble tillage can be taken into consideration.     

Effects of autumn tillage and residue management on soil respiration in a long‐term field experiment in Sweden

Several previous field studies in temperate regions have shown decreased soil respiration after conventional tillage compared with reduced or no‐tillage treatments. Whether this decrease is due to differences in plant residue distribution or changes in soil structure following tillage remains an open question. This study investigated (1) the effects of residue management and incorporation depth on soil respiration and (2) biological activity in different post‐tillage aggregates representing the actual size and distribution of aggregates observed in the tilled layer. The study was conducted within a long‐term tillage experiment on a clay soil (Eutric Cambisol) in Uppsala, Sweden. After 38 y, four replicate plots in two long‐term treatments (moldboard plowing (MP) and shallow tillage (ST)) were split into three subplots. These were then used for a short‐term trial in which crop residues were either removed, left on the surface or incorporated to about 6 cm depth (ST) or at 20 cm depth (MP). Soil respiration, soil temperature, and water content were monitored during a 10‐d period after tillage treatment. Respiration from aggregates of different sizes produced by ST and MP was also measured at constant water potential and temperature in the laboratory. The results showed that MP decreased short‐term soil respiration compared with ST or no tillage. Small aggregates (< 16 mm) were biologically most active, irrespective of tillage method, but due to their low proportion of total soil mass they contributed < 1.5% to total respiration from the tilled layer. Differences in respiration between tillage treatments were found to be attributable to indirect effects on soil moisture and temperature profiles and the depth distribution of crop residues, rather than to physical disturbance of the soil.     

A comparison between seasonal changes in soil water storage and penetration resistance under conventional and conservation tillage systems in Aragón

Low and extremely variable precipitations limit dryland crop production in the semi-arid areas of Aragón (NE Spain). These areas are also affected by high annual rates of topsoil losses by both wind and water erosion. A long-term experiment to determine the feasibility of conservation tillage in the main winter barley production areas of Aragón was initiated in 1989 at four locations, three on loam to silt loam soils (Xerollic Calciorthid) and one on a silty clay loam (Fluventic Ustochrept), receiving between 300 and 600 mm of average annual rainfall. In this study, we compared, under both continuous cropping and cereal-fallow rotation, the effects of conventional tillage (mouldboard plough) and two conservation tillage systems, reduced tillage (chisel plough) and no-tillage, on soil water content and penetration resistance during the first two growing seasons. Whereas reduced and conventionally tilled treatments generally had similar soil water content during the experimental period, the effects of no-tillage were inconsistent. No-tilled plots had from 26% less to 17% more stored soil water (0–80 cm) than conventional tilled plots at the beginning of the growing season. In contrast to the conventional and reduced tillage treatments, penetration resistances were between 2 and 4 MPa after sowing in most of the plough layer (0–40 cm) under no-tillage at all sites. Fallow efficiencies in moisture storage in the cereal-fallow rotation, when compared with the continuous cropping system, ranged from −8.7 to 12%. The highest efficiencies were recorded when the rainfall in the months close to primary tillage exceeded 100 mm. Since this event is very unlikely, long fallowing (9–10 months) appears to be an inefficient practice for water conservation under both conventional and conservation management. Our results suggest that, up to now, only reduced tillage could replace conventional tillage without adverse effects on soil water content and penetration resistance in the dryland cereal-growing areas of Aragón.     

Tillage erosion within potato production systems in Atlantic Canada: I. Measurement of tillage translocation by implements used in seedbed preparation

In Canada, there is growing acceptance that tillage erosion is a serious form of soil degradation and a threat to the sustainability of agriculture across the country. To date, the potential risk for tillage erosion within potato production systems has not been investigated. The objective of this study was to generate tillage translocation values for primary and secondary tillage implements common to seedbed preparation within conventionally and conservation tilled potato production systems in Atlantic Canada. Tillage translocation was measured for each implement by labelling a plot of soil with a tracer. The tracer redistribution along the path of tillage was used to generate a summation curve to calculate mean soil movement in the direction of tillage. The results show that each primary and secondary tillage operation moved vast quantities of soil and is potentially erosive. Maximum displacement distances were considerably larger in this project than those reported in previous studies looking at tillage erosion by primary and/or secondary tillage implements. All four tillage implements tested moved soil at least 3 m, with the greatest translocated distances (5.6 m) observed for the chisel plough (CP) and vibrashank (VS). The mass of translocated soil (T_M) was greatest for the CP, followed by the mouldboard plough (MP), VS and offset disc (OD). In addition, compared to travelling downslope, the upslope speed of tillage was reduced by 38%, 21%, 32% and 12% for the MP, CP, OD and VS, respectively, while the depth of tillage was reduced by 6%, 5%, 35% and 2%, respectively. It is apparent that conservation tillage implements (the CP is generally promoted to reduce water erosion in Atlantic Canada) and secondary tillage implements (OD and VS) can move as much soil as conventional tillage implements such as the mouldboard plough, and must be considered when developing plans to reduce soil erosion within potato fields in Atlantic Canada.     

Reduced tillage in temperate organic farming: implications for crop management and forage production

To promote conservation tillage in organic farming systems, weed control and ley removal within arable-ley rotations need to be optimized. A long-term field trial was thus established in Frick, Switzerland in 2002 on a clayey soil and with a mean precipitation of 1000 mm/year. The tillage experiment distinguished between conventional tillage with mouldboard ploughing (CT, 15 cm depth) and reduced tillage (RT), including a chisel plough (15 cm) and a stubble cleaner (5 cm). Results of a 2-year grass-clover ley (2006/2007) and silage maize (2008) are presented. Due to dry conditions, mean grass-clover yields were 25% higher in RT than in CT, indicating better water retention of RT soils. Clover cover and mineral contents of the fodder mixture were also higher in RT. The ley was successfully removed in autumn 2007 in RT plots, and a winter pea catch crop was sown before maize. In CT, ploughing took place in spring 2008. Maize yields were 34% higher in RT than in CT, despite a two- to three-fold higher but still tolerable weed infestation. Maize in RT plots benefited from an additional 61.5 kg of easily decomposable organic N/ha incorporated into the soil via the pea mulch. Measurement of arbuscular mycorrhizal colonization of maize roots indicated a similar mechanical disturbance of the topsoil through the reduced ley removal system compared with ploughing. It is suggested that RT is applicable in organic farming, even in arable-ley rotations, but long-term effects need further assessment.     

Effects of tillage depth on organic carbon content and physical properties in five Swedish soils

The soil tillage system affects incorporation of crop residues and may influence organic matter dynamics. A study was carried out in five 15–20 year old tillage experiments on soils with a clay content ranging from 72 to 521 g kg⁻¹. The main objective was to quantify the influence of tillage depth on total content of soil organic carbon and its distribution by depth. Some soil physical properties were also determined. The experiments were part of a series of field experiments all over Sweden with the objective of producing a basis to advise farmers on optimal depths and methods of primary tillage under various conditions. Before the experimental period, all sites had been mouldboard ploughed annually for many years to a depth of 23–25 cm. Treatments included primary tillage to 24–29 cm depth by mouldboard plough (deep tillage) and to 12–15 cm by field cultivator or mouldboard plough (shallow tillage). Dry bulk density, degree of compactness and penetration resistance profiles clearly reflected the depth of primary tillage and substantially increased below that depth. Compared to deep tillage, shallow tillage increased the concentration of organic carbon in the surface layer but decreased it in deeper layers. Total quantity of soil organic carbon and carbon–nitrogen ratio were unaffected by the tillage depth. Thus, a reduction of the tillage depth from about 25 cm to half of that depth would appear to have no significant effect on the global carbon cycle.     

Characterization of soil physical properties and organic matter under long-term primary tillage in a humid climate

Chisel ploughing is considered to be a potential conservation tillage method to replace mouldboard ploughing for annual crops in the cool-humid climate of eastern Canada. To assess possible changes in some soil physical and biological properties due to differences in annual primary tillage, a study was conducted for 9 years in Prince Edward Island on a Tignish loam, a well-drained Podzoluvisol, to characterize several mouldboard and chisel ploughing systems (at 25 cm), under conditions of similar crop productivity. The influence of primary tillage on the degree of soil loosening, soil permeability, and both organic matter distribution throughout the soil profile and organic matter content in soil particle size fractions was determined. At the time of tillage, chisel ploughing provided a coarser soil macrostructure than mouldboard ploughing. Mouldboard ploughing increased soil loosening at the lower depth of the tillage zone compared to chisel ploughing. These transient differences between primary tillage treatments had little effect on overall soil profile permeability and hydraulic properties of the tilled/non-tilled interface at the 15–30 cm soil depth. Although soil microbial biomass, on a volume basis, was increased by 30% at the 0–10 cm soil depth under chisel ploughing, no differences were evident between tillage systems over the total tillage depth. Mouldboard ploughing increased total orgainc carbon by 43% at the 20–30 cm soil depth, and the carbon and nitrogen in the organic matter fraction ≤ 53 μm by 18–44% at the 10–30 cm soil depth, compared to chisel ploughing.     

Spatial distributions of soil chemical and physical properties prior to planting soybean in soil under ridge‐, no‐ and conventional‐tillage in a maize–soybean rotation

Detailed information on the profile distributions of agronomically important soil properties in the planting season can be used as criteria to select the best soil tillage practices. Soil cores (0–60 cm) were collected in May, 2012 (before soybean planting), from soil transects on a 30‐yr tillage experiment, including no‐tillage (NT), ridge tillage (RT) and mouldboard plough (MP) on a Brookston clay loam soil (mesic Typic Argiaquoll). Soil cores were taken every 19 cm across three corn rows and these were used to investigate the lateral and vertical profile characteristics of soil organic carbon (SOC), pH, electrical conductivity (EC), soil volumetric water content (SWC), bulk density (BD), and penetration resistance (PR). Compared to NT and MP, the RT system resulted in greater spatial heterogeneity of soil properties across the transect. Average SOC concentrations in the top 10 cm layer were significantly greater in RT than in NT and MP (P = 0.05). NT soil contained between 0.8 and 2.5% (vol/vol) more water in the top 0–30 cm than RT and MP, respectively. MP soil had lower PR and BD in the plough layer compared to NT and RT soils, with both soil properties increasing sharply with depth in MP. The RT had lower PR relative to NT in the upper 35 cm of soil on the crop rows. Overall, RT was a superior conservation tillage option than NT in this clay loam soil; however, MP had the most favourable soil conditions in upper soil layers for early crop development across all treatments.     

Simulation of the redistribution of soil by tillage on complex topographies

Tillage redistributes soil and contributes significantly to the within‐field soil variation, especially on topographically complex terrain. Although the basic principles of the redistribution are well understood, models for simulating the redistribution are poor predictors. This paper presents a modelling structure that allows a simulation of the redistribution of soil constituents on complex topographies for various tillage implements. The model simulates the redistribution of soil constituents by convoluting the probability distribution of the tillage displacement with the spatial distribution of the soil constituents. The probability distributions in two dimensions are derived from a series of tillage experiments conducted with a mouldboard plough at various positions in the landscape. Furthermore, the effects of topography and tillage direction on the probability distributions were characterized and implemented in the model. A first application showed that the direction of tillage significantly affects the long‐term redistribution of soil constituents. The inclusion of other implements in the model was explored, and we found that data in the literature could be used for simulating the long‐term effects of tillage.     

A simplified modelling approach for quantifying tillage effects on soil carbon stocks

Soil tillage has been shown to affect long‐term changes in soil organic carbon (SOC) content in a number of field experiments. This paper presents a simplified approach for including effects of tillage in models of soil C turnover in the tilled‐soil layer. We used an existing soil organic matter (SOM) model (CN‐SIM) with standard SOC data for a homogeneous tilled layer from four long‐term field experiments with conventionally tilled (CT) and no‐till (NT) treatments. The SOM model was tested on data from long‐term (>10 years) field trials differing in climatic conditions, soil properties, residue management and crop rotations in Australia, Brazil, the USA and Switzerland. The C input for the treatments was estimated using data on crop rotation and residue management. The SOM model was applied for both CT and NT trials without recalibration, but incorporated a ‘tillage factor’ (TF) to scale all decomposition and maintenance parameters in the model. An initial value of TF = 0.57 (parameter uncertainty, PU = 0.15) for NT (with TF set to 1.0 for CT) was used on the basis of a previous study with observations of soil CO₂ respiration. The simulated and observed changes in SOC were then compared using slopes of linear regressions of SOC changes over time. Results showed that the SOM model captured observed changes in SOC content from differences in rotations, N application and crop residue management for conventional tillage. On the basis of SOC change data a mean TF of 0.48 (standard deviation, SD = 0.12) was estimated for NT. The results indicate that (i) the estimated uncertainty of tillage effects on SOC turnover may be smaller than previously thought and (ii) simple scaling of SOM model parameters may be sufficient to capture the effects of soil tillage on SOM turnover in the tilled layer. Scenario analyses showed that the average extra C input needed to compensate for soil tillage was 762 (SD = 351) kg C ha⁻¹ year⁻¹. Climatic conditions (temperature and precipitation) also affected how much extra C was needed, with substantially larger inputs being required for wetter and warmer climates.     

Optimized soil inversion in the headlands with a novel section-controlled mouldboard ploughing system

In inversion tillage systems, the mouldboard plough is fundamental for producing a desirable seedbed. The desired ploughing quality is achieved when the plough layer is inverted homogeneously. This is, however, difficult to obtain in the main-headland intersection zone where the plough is lowered and elevated, as ploughed and unploughed triangles are formed. This results in zones where the soil is inverted twice, which may result in poor residue and weed incorporation and a poor seedbed quality. The design of the three-point linkage-attached mouldboard plough has not changed since the 1950s, but the number of furrows has increased, which has increased the size of the aforementioned triangles. A novel ploughing system was introduced to meet these headland challenges, where each plough section can be lowered and elevated independently. The aim of this study was to evaluate the effects of using a section-controlled mouldboard plough. Two similarly designed, randomized, field plot experiments were conducted on two different soil types (sandy loam and loamy sand) on a stubble field and grass field. The study showed that the section-controlled plough reduced the main-headland overlap area by ~98%. The results of a range of soil physical properties measurements and seedbed quality analyses showed that the section-controlled plough created a homogeneous loosened seedbed quality, improving the incorporation of crop residues and leaving fewer residues on the soil surface. Furthermore, the section-controlled plough showed additional benefits, for example wedge operations and visual line marking.     

Traffic and tillage effects on soil conditions and crop growth on a swelling clay soil

Abstract. Trafficked and non-trafficked (12 m gantry) crop production systems, which had been maintained on an Evesham series 60% clay soil since 1986, were used again in 1993 during the cultivation and sowing of winter wheat. After a one year set-aside break, mouldboard ploughing, tine cultivation and rotary digging were compared. Measurements were made of tillage energy, soil tilth, cone penetration resistance, biological activity and crop performance, and on specific plots, soil density, seedbed tilth and water release characteristics. Despite the one year's set-aside break, the effect of the previously applied traffic treatments remained and resulted in a smaller specific plough resistance and tillage energy on the non-trafficked soil. Tine cultivator draught however was greater on the non-trafficked compared with the trafficked plots. The specific energy required for rotary digging on non-trafficked soil was similar to that required during the ploughing of similar plots. A measure of indefinite biotic activity indicated that this was apparently greater on the non-traffficked soil, while soil density was decreased by up to 18% in these conditions compared with the trafficked land. Average cone resistance over the depth range 0 to 0.5 m was 1.51 MPa on the trafficked, compared with 1.24 MPa on the non-trafficked soil. Cone resistance also tended to be greater after tine cultivation compared with that after ploughing. Water release curves were interpreted as showing more macropores within the topsoil of the non-trafficked compared with the trafficked plots. Tine cultivation on trafficked soil had more smaller pores than mouldboard plough cultivation. Winter wheat yield was increased by 25% (from 8 to 10 t/ha) on non-trafficked compared with trafficked soil.     

Saltation transport on a silt loam soil in northeast Spain

The Ebro River valley in Northeast Spain experiences regularly strong west-northwest winds that are locally known as cierzo . When the cierzo blows, wind erosion may potentially occur on unprotected agricultural lands. In this paper the first results of field measurements of soil characteristics and saltation transport in the Ebro River valley near Zaragoza are presented. An experiment was conducted on a silt loam soil in the summers of 1996 and 1997. Two plots of 135×180 m were both equipped with a meteorology tower, three saltiphones (acoustic sediment sensors) and ten sediment catchers. The plots were different with respect to tillage practices. One plot received mouldboard ploughing followed by a pass of a compacting roller (conventional tillage—CT), whereas the other plot only received chisel ploughing (reduced tillage—RT). Soil characterizations indicated that soil erodibility was significantly higher in the CT plots than in the RT plots. Consequently, no significant saltation transport was observed in the RT plots during both seasons. In the CT plot, four saltation events were recorded during the 1996 season and nine events during the 1997 season. Most events were preceded by rainfall during the previous one or two days, which reduced saltation transport significantly. It is concluded that the occurrence of wind erosion in the Ebro River valley depends on the timing and type of tillage, distribution of rainfall and soil-surface crusting. Copyright © 1999 John Wiley & Sons, Ltd.     

Response of soil structure and hydraulic conductivity to reduced tillage and animal manure in a temperate loamy soil

We studied the combined effects of reduced tillage and animal manure on soil structure and hydraulic conductivity (K) in the 2–10 and 12–20 cm layers in a loamy soil. The study was performed at the end of a 7‐yr field trial and included three tillage treatments (mouldboard ploughing until 25 cm depth: MP, shallow tillage until 12 cm depth: ST, no‐till: NT) and two fertilizer application treatments (mineral or poultry manure). Soil structure was assessed through bulk density (ρ_b), micromorphological and macropore‐space characteristics. K was measured in situ at ?0.6, ?0.2 and ?0.05 kPa. Untilled layers had a vermicular microstructure resulting from earthworm activity, whereas tilled layers displayed a mixture of crumb and channel microstructures. Untilled layers had the highest ρ_b and twice as much lower total macroporosity area (pores > 240 μm in equivalent diameter) than tilled layers, reflected by the smallest area of macropores 310–2000 μm in diameter and the smallest area of large complex macropores. K under untilled layers was 12–62% lower than that under tilled layers, but differences were statistically significant only at ?0.05 kPa in the 2–10 cm. No significant interaction between tillage and nutrient application treatments was detected for all properties. Compared with mineral fertilizer, poultry manure resulted in a similar ρ_b but 20% greater total macroporosity area and 30% higher K at ?0.2 kPa. Overall, the sensitivity of soil structure and K to poultry manure were relatively small compared with tillage. We suggest that cultivation practices other than animal manure application are needed to improve physical properties under reduced tillage.     

Tillage erosion within potato production in Atlantic Canada: II: Erosivity of primary and secondary tillage operations

To date, tillage erosion experiments in Canada have only been conducted on conventionally tilled corn-based production systems in Ontario and conventionally tilled cereal-based production in Manitoba. Estimates and assumptions have been made for all other production systems. Therefore, the objective of this study was to evaluate the erosivity of primary and secondary tillage operations within conventional and conservation potato production systems used in Atlantic Canada. Regression analysis determined that a direct relationship exists between slope gradient and both the mean displacement distance of the tilled layer (T_L) and the mass of translocated soil (T_M) for the chisel plough (CP), mouldboard plough (MP) and offset disc (OD), but not for the vibrashank (VS). Overall, the potential for tillage erosion of the MP, CP, and OD was similar (1.8–1.9 kg m⁻¹ %⁻¹ pass⁻¹) and larger than that of the VS (0.3 kg m⁻¹ %⁻¹ pass⁻¹). The regression coefficients for each implement were improved after including slope curvature, and we recommend that curvature be included in any future tillage erosion modelling. Our results show that both residue management to control wind and water erosion and soil movement to control tillage erosion must be considered when choosing implements and developing best management practices with regards to reducing the negative impacts of total soil erosion on potato production systems in Atlantic Canada.     

轮耕对土壤物理性状和冬小麦产量的影响

针对华北地区土壤连续单一耕作存在的主要问题,进行了土壤轮耕效应的研究。试验选择冬小麦夏玉米玉两熟区连续5 a免耕田,设置免耕、翻耕和旋耕3种轮耕处理（即免耕一免耕,免耕一翻耕和免耕一旋耕）,冬小麦播种前进行耕作处理。研究结果表明：多年免耕后进行土壤耕作（翻耕、旋耕）可以显著降低土壤体积质量;旋耕显著降低0～10 cm土壤体积质量,翻耕则降低0～20 cm体积质量;随时间变化各处理土壤体积质量差异逐渐降低。翻耕、旋耕均显著增加了0～10 cm土壤总孔隙,同时翻耕显著增加了10～20 cm土壤总孔隙;翻耕、旋耕显著提高了5～10 cm毛管孔隙。0～10 cm土壤饱和导水率表现为旋耕＞翻耕＞免耕,翻耕、旋耕在5%水平上显著高于免耕;10～20、20～30 cm土层均表现为翻耕＞旋耕＞免耕,且10～20 cm翻耕5%水平上显著高于免耕;饱和导水率与体积质量呈显著线性负相关。翻耕、旋耕有效穗数与免耕相比分别提高了24.1%、22.3%;冬小麦的实际产量表现为：旋耕＞翻耕＞免耕,翻耕、旋耕分别比免耕增产11.8%、16.9%。总之,长期免耕后进行土壤耕作有利于改善土壤物理性状,提高作物产量。