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1.
长期秸秆还田免耕覆盖措施导致沿淮区域砂姜黑土耕层变浅、下表层(10~30 cm)容重增加、土壤养分不均衡等问题凸显,限制了小麦-玉米周年生产力的提高。耕作和秸秆还田措施合理的搭配组合是解决这一问题的有效方法。通过8年的小麦-玉米一年两熟田间试验,设置4个处理:1)玉米季免耕-小麦季免耕秸秆不还田(N);2)玉米季深耕-小麦季深耕秸秆不还田(D);3)玉米季秸秆免耕覆盖还田+小麦秸秆免耕覆盖还田(NS);4)玉米季秸秆免耕覆盖还田+小麦季秸秆深耕还田(DS)。通过分析作物收获后不同土壤深度(0~60 cm)总有机碳(TOC)、颗粒态碳(POC)、微生物生物量碳(MBC)、易氧化态碳(KMnO4-C)、可溶性有机碳(DOC)和土壤碳库管理指数(CPMI),并结合小麦-玉米的周年产量变化,以期获得培肥砂姜黑土的最佳模式。研究结果表明:1)相对于长期免耕措施(N),DS处理能够提高0~30 cm土层TOC、POC、MBC、KMnO4-C等组分含量和CPMI;而NS措施仅提高土壤表层(0~10 cm)TOC、活性有机碳组分含量和CPMI;2)DS处理显著提升了小麦-玉米的周年生产力,其麦玉的周年产量均值分别比N、D和NS处理高出14.7%、12.9%和8.5%;3)MBC和KMnO4-C对于耕作和秸秆还田措施都是较为敏感指示因子。总的来说,玉米季小麦秸秆覆盖还田+小麦季玉米秸秆深耕还田(DS)是改善沿淮地区砂姜黑土土壤碳库、提高小麦-玉米周年产量的一种有效农田管理模式。  相似文献   

2.
Crop residue management strategies must be adapted for improving carbon (C) balance and soil C stock in agroecosystems in sub‐Saharan Africa with consideration of the crop residue availability and site‐specific soil characteristics. We conducted field experiments to determine the effects of crop residue application method (incorporation/mulching) and quality (maize/cowpea) and N fertilizer application on the soil respiration rate and soil C stock in the surface soil layer (0–15 cm) in maize croplands with contrasting soil textures (clay/sandy) over 2 years from 2012 to 2014 in Tanzania. At the clay site, the incorporation of maize residues showed a 38% increase in CO2 flux compared to mulching, whereas, at the sandy site, mulching showed a 16% increase compared to the incorporation. At the sandy site, mulching practice retained soil moisture content and apparently enhanced the decomposition of the original soil organic C in the surface layer. It is, therefore, suggested that mulching practice may accelerate a long‐term depletion of soil C stock at the sandy site. The cowpea residue incorporation led to rapid decomposition because of its high biodegradability at both sites. The N fertilizer application stimulated the decomposition of labile soil organic matter. The soil C stock in the surface layer did not significantly change after the 2‐year experiment, irrespective of crop residue treatment and soil type. In conclusion, adequate crop residue management in terms of suppressing CO2 flux during a cropping season depends on soil type, but the long‐term effect on soil C stock is unclear.  相似文献   

3.
Soil erosion is a problem in the Southeastern Coastal Plain of the U.S.A. where clean tillage row cropping exists without adequate soil conserving practices. Conservation tillage practices in the region have frequently incorporated in-row subsoiling to overcome root restricting soil layers 0.20 to 0.35 m below the surface. A number of studies have been conducted to determine the benefits of in-row subsoiling and results have been contradictory. The objective of this study was to evaluate the relationships between in-row subsoil and non-subsoil tillage treatments, soil water, and corn grain yields.The study was conducted for two years on an Orangeburg sandy loam (Typic Paleudult). The study contained irrigated and non-irrigated treatments. The four tillage treatments used were (T1) in-row subsoiler followed by a double disk bedder, (T2) double disk bedder, (T3) fluted coulter followed by in-row subsoiler and slot filler tines, and (T4) fluted coulter. Tillage and planting were accomplished simultaneously. Each corn (Zea Mays L. ‘Dekalb XL72B’) crop was preceded by fall-planted wheat and the wheat (Triticum aestivium L. “Coker 747”) was killed with herbicides in the spring before corn planting. Wheat mulch was disked in prior to the bedding treatments and left undisturbed for the two fluted coulter treatments. Corn was planted 0.04 m deep with double disk openers. Soil water potential was maintained above 0.05 MPa in the irrigated corn plots. Forty kg/ha of N was applied at planting and followed 42 days later with eight weekly applications of 50 kg/ha N.In-row subsoiling and irrigation treatments significantly increased grain yields. Irrigated corn grain yields were 12333 and 7872 kg/ha in 1978 and 1979, respectively. Non-irrigated corn yields were 7697 and 4892 kg/ha in 1978 and 1979, respectively. In-row subsoiled to a depth of 0.36 m and non-subsoiled grain yields were 8577 and 7820 kg/ha, respectively. There was no significant difference between bedding and fluted coulter treatments.  相似文献   

4.
江苏省稻麦复种合理轮耕制的研究   总被引:10,自引:0,他引:10       下载免费PDF全文
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5.
《Journal of plant nutrition》2013,36(12):2343-2364
Abstract

A two‐year study (1997–1999) was conducted on a sandy clay loam (Typic Paleudult) at the experimental farm of the Universiti Putra to determine the effects of application of crop residues on changes of some soil properties in a maize (Zea mays L.)–groundnut (Arachis hypogaea) crop rotation system. Five crops of a rotation of sweet corn–groundnut–sweet corn–groundnut–sweet corn were sown with three treatments: recommended inorganic fertilizer [nitrogen (N), phosphorus (P), and potassium (K)] with crop residue (T1), recommended inorganic fertilizer without crop residues (T2) or one‐half of the recommended inorganic fertilizer with crop residues combined with 10 t ha?1 of chicken manure (T3). Soil organic carbon (OC), soil water content and soil bulk density were not significantly changed. Application of crop residues for two years increased cation exchange capacity (CEC) whereas supplementing crop residues with CM had significantly increased soil pH of the topsoil. Phosphorous in manure treatment had moved down the soil profile, which might cause eutriphication of under ground water, particularly during the rainy season. Based on this work, incorporation of crop residues could be a beneficial practice for improving the fertility of acid soils.  相似文献   

6.
This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration.

This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.  相似文献   


7.
 In long-term field experiments on sandy loam and loamy sand soils, the influence of conservation and conventional tillage on soil and rhizosphere microorganisms was studied. Conservation tillage stimulated rhizosphere bacteria on winter wheat, winter barley, winter rye and maize in different soil layers. Particularly the populations of Agrobacterium spp. and Pseudomonas spp. were increased. On the sandy loam, N2 fixation and nodulation of pea plants were significantly increased. No influence of different soil tillage was determined on the colonization of the rhizosphere by mycorrhiza and saprophytic fungi. Stubble residues infected with Gaeumanomyces graminis were infectious for a longer time on the soil surface than after incorporation into the soil. Received: 10 March 1998  相似文献   

8.
稻麦两熟条件下不同土壤耕作方式与秸秆还田效用分析   总被引:36,自引:8,他引:36  
该文通过大田小区和网室水泥池微区的3年定位试验,比较研究了稻麦两熟条件下免耕秸秆覆盖、免耕高茬、翻耕秸秆还田(秸秆稻季翻埋麦季覆盖)、翻耕(对照,CK)4个处理对土壤理化性质和稻麦产量的影响,从土壤管理技术方面探讨了不同耕作方法与秸秆直接还田在稻麦两熟地区的应用效果。结果表明:免耕使土壤容重和穿透阻力增加,而秸秆还田可改善土壤结构,提高土壤养分含量,翻耕还田3年后土壤有机质、全氮、速效磷、速效钾含量比对照分别增加4.7%~13.0%、0%~10.6%、0.2%~10.6%、8.4%~15.5%。麦季秸秆还田的产量有增有减,实际产量免耕覆盖还田略低,对照的产量较高,秸秆还田平均减产1%左右;而水稻翻耕秸秆还田的产量最高,比对照平均增产3%左右。因此,在稻麦两熟条件下,从省工节本和提高地力角度可采用稻麦免耕秸秆覆盖与留高茬还田,从提高产量和地力角度宜采用稻季翻耕秸秆还田。  相似文献   

9.
The continuous use of heavy machinery and vehicular traffic on agricultural land led to an increase in soil compaction, which reduces crop yield and deteriorates the physical conditions of the soil. A pot experiment was conducted under greenhouse conditions to study the effects of induced soil compaction on growth and yield of two wheat (Triticum aestivum) varieties grown under two different soil textures, sandy loam and sandy clay loam. Three compaction levels [C0, C1, and C2 (0, 10 and 20 beatings)], two textural classes (sandy loam and sandy clay loam), and two genotypes of wheat were selected for the experiment. Results indicated that induced soil compaction adversely affected the bulk density (BD) and total porosity of soil in both sandy loam and sandy clay loam soils. Compaction progressively increased soil BD from 1.19 Mg m?3 in the control to 1.27 Mg m?3 in C1 and 1.40 Mg m?3 in C2 in sandy loam soil while the corresponding increase in BD in sandy clay loam was 1.56 Mg m?3 in C1 and 1.73 Mg m?3 in C2 compared to 1.24 Mg m?3 in the control. On the other hand, compaction tended to decrease total porosity of soil. In case of sandy loam, porosity declined by 5% and 17% in C1 and C2, respectively, and declined in sandy clay loam by 29% and 54%, respectively. Averaged over genotypes and textures, shoot length decreased by 15% and 26% at C1 and C2, respectively, and straw yield decreased by 21% and 61%, respectively. The compaction levels C1 and C2 significantly decreased grain yield by 12% and 41%, respectively, over the control. The deleterious effect of compaction was more pronounced on root elongation and root mass, and compaction levels C1 and C2 decreased root length by 47% and 95% and root mass by 41% and 114%, respectively, over the control. Response of soil texture to compaction was significant for almost all the parameters, and the detrimental effects of soil compaction were greater in sandy clay loam compared to sandy loam soil. The results from the experiment revealed that soil compaction adversely affected soil physical conditions, thereby restricting the root growth, which in turn may affect the whole plant growth and grain yield. Therefore, appropriate measures to avoid damaging effects of compaction on soil physical conditions should be practiced. These measures may include soil management by periodic chiseling, controlled traffic, conservation tillage, addition of organic manures, and incorporating crops with deep tap root systems in a rotation cycle.  相似文献   

10.
Abstract

Soil carbon sequestration in agricultural lands has been deemed a sustainable option to mitigate rising atmospheric CO2 levels. In this context, the effects of different tillage and C input management (residue management and manure application) practices on crop yields, residue C and annual changes in total soil organic C (SOC) (0–30 cm depth) were investigated over one cycle of a 4-year crop rotation (2003–2006) on a cropped Andisol in northern Japan. For tillage practices, the effects of reduced tillage (no deep plowing, a single shallow harrowing for seedbed preparation [RT]) and conventional deep moldboard plow tillage (CT) were compared. The combination of RT, residue return and manure application (20 Mg ha?1 in each year) increased spring wheat and potato yields significantly; however, soybean and sugar beet yields were not influenced by tillage practices. For all crops studied, manure application enhanced the production of above-ground residue C. Thus, manure application served not only as a direct input of C to the soil, but the greater crop biomass production engendered enhanced subsequent C inputs to the soil from residues. The SOC contents in both the 0–5 cm and 5–10 cm layers of the soil profile were greater under RT than under CT treatments because the crop residue and manure were densely incorporated into the shallow soil layers. Comparatively, neither tillage nor C input management practices had significant effects on annual changes in SOC content in either the 10–20 cm or 20–30 cm layers of the soil profile. When soil C sequestration rates, as represented by annual changes in total SOC (0–30 cm), were assessed on a total soil mass basis, an anova showed that tillage practices had no significant effect on total C sequestration, but C input management practices had significant positive effects (P ≤ 0.05). These results indicate that continuous C input to the soil through crop residue return and manure application is a crucial practice for enhancing crop yields and soil C sequestration in the Andisol region of northern Japan.  相似文献   

11.
In no-tillage (NT) system, precedent crop residue retains on the soil surface to preserve soil water for crop growth. In response to the negative impact of soil degradation under conventional tillage (CT) system based on soil tillage, NT system without tillage practice and with protective cover of crop residue is being developed in many parts of the world. However, NT is a successful system especially in the South of America, but the impacts of this system on the Mediterranean climate especially in the southeast (SE) of France is less known; therefore, this study has been carried out within the scope of a European project. Durum wheat and corn were sown under CT and NT. Time requirement and fuel consumption in these two systems were measured. The results showed that durum wheat and corn yields were the same in both systems except of 2008, while work duration and energy requirement were 87% and 83% lower in NT system, respectively. Furthermore, NT could mitigate CO2 emission up to 50% as compared with CT. These results show that NT can be considered as a relevant alternative for CT regarding economical and environmental advantages.  相似文献   

12.
The effects of seedbed tilth (coarse and fine) and different levels of nitrogen application (0–150 kg/ha N) on wheat response were studied in loam and sandy loam alluvial soils (Typic Camborthids) at three sites under irrigated conditions. The percentage of dry aggregates > 4 mm was 36.7 and 50.8 at site 2 and > 10 mm was 44.3 and 70.2 at site 3 under fine- and coarse-tilth treatments, respectively. The variations in soil tilth were obtained either by use of different types of tillage implements, their combinations and sequence, or by variation in soil moisture content at the time of cultivation. Crop growth was better and grain yields under coarse-tilth were from 0.3 (0 N) to 1.2 t/ha (150 N) higher than under fine-tilth. Total mineral nitrogen (NO3-N and NH4-N) content was larger in coarse-tilth treatments than in fine-tilth treatments.  相似文献   

13.
Abstract. The effects of deep tillage, straw mulching and farmyard manure on maize growth in loamy sand and sandy loam soils were studied in experiments lasting three years. Treatments included all combinations of conventional tillage (10 cm deep) and deep tillage (35–40 cm deep), two farmyard manure rates (0 and 15 t/ha) and two mulch rates (0 and 6 t/ha), replicated three times in a randomixed block design.
Deep tillage decreased soil strength and caused deeper and denser rooting. Mulching decreased maximum soil temperature and kept the surface layers wetter resulting in better root growth. Farmyard manure also improved root growth, and the crop then extracted soil water more efficiently. All three treatments increased grain yield in the loamy sand, but in the sandy loam only tillage and farmyard manure increased yields significantly. Deep tillage and straw mulch effects varied with soil type and amount of rainfall in the growing season. In the loamy sand the mean responses to deep tillage and mulching were largest in a dry year. A tillage-mulch interaction was significant in the loamy sand.  相似文献   

14.
Abstract

Importance of agricultural practices for greenhouse gases mitigation is examined worldwide. However, there is no consensus on CO2 emissions as affected by soil management practices. Deeper understanding of soil CO2 fluxes and drivers under different management practices are needed. The investigation of net CO2 exchange rate as dependent variable and drivers (soil water and temperature, air temperature) as affected by soil type (loam and sandy loam), tillage (conservation and no-tillage) and fertilization are presented.

Soil management practices and weather conditions affected the CO2 flux through effects on soil water and temperature regime. Mean net CO2 exchange rate on sandy loam was 8% higher than on loam. No-tillage, as a moisture-conserving tool, could be an appropriate tool for CO2 emissions mitigation in any weather conditions on sandy loam; however, the advantage of no-tillage on loam was negligible. Mineral NPK fertilizers promoted significantly higher net CO2 exchange rate in both soils, but suppressed it by 15% on sandy loam during a normal year. Effect of soil water content on net CO2 exchange rate was direct in all tillage and fertilization treatments in both loam and sandy loam, whereas this effect was positive only in dry and normal weather conditions. In wet weather conditions, the direct effect of soil water content on net CO2 exchange rate was negative. Soil and air temperature acted indirectly on net CO2 exchange rate. The increase in temperature markedly suppressed the positive direct impact of soil water content on net CO2 exchange rate in dry weather conditions, but did not reduce the direct effect of soil water content in normal weather conditions. In a wet year the negative indirect effect of increased temperature enhanced the negative direct impact of soil water surplus on net CO2 exchange rate.  相似文献   

15.
Reduced tillage systems may be an option to allow rapid crop establishment in areas constrained by a short growing season, but such methods need to be adapted to soil tillage requirement and crop establishment needs. Rotation and tillage studies were conducted during a 6-year period on a fine sandy loam (Podzol) with silage maize (Zea mays L.) under the cool, humid climate, and relatively short growing season of Prince Edward Island, Atlantic Canada. The objective was to compare a continuous maize rotation with a maize–barley (Hordeum vulgare L.) rotation, using both no-tillage and conventional mouldboard ploughing for the maize, and to evaluate treatment effects on maize growth and productivity, weed populations, and soil quality. Plant population and maize yield were not consistently influenced by the tillage or rotation treatments. Mean maize yield ranged from 7.2 to 7.7 Mg ha−1. An increasing density of weeds over the 6-year period, especially perennial species, was evident under no-tillage, compared to mouldboard ploughing. Except for slight changes in soil pH, spatial variation in extractable soil P, and a higher level of organic C and labile forms of C (microbial biomass and mineralizable C), soil chemical quality was similar among treatments. An apparent decline in soil physical quality, as indicated by a reduction in macro-porosity volume and increase in soil penetration resistance below the 8 cm soil depth, was evident under the no-tillage at the end of the 6-year period. However, macro-pore continuity was less affected by a reduction in tillage, while field measurements of soil hydraulic conductivity increased under no-tillage compared to ploughing. The latter result may be related to the observed increase in earthworm population where tillage was reduced. Use of rotational tillage resulted in an intermediate soil physical condition between continuous no-tillage and ploughing. Overall, no-tillage appears a promising strategy to facilitate a fast and early establishment of maize on sandy loam soils in Atlantic Canada, but some ongoing monitoring of the soil physical condition would be required.  相似文献   

16.
Despite a vast amount of data on the effect of tillage on crop productivity, surprisingly there is little detailed information available on the influence on below and aboveground crop growth dynamics. Such information is essential for developing sustainable cropping systems. The objective of this study was to investigate the effect of tillage intensity on crop growth dynamics and soil structure. A tillage experiment was established in autumn 2002 on two Danish sandy loams (Foulum and Flakkebjerg) in a cereal‐based crop rotation. The tillage systems included in this study were direct drilling (D), harrowing 8–10 cm (H8‐10), and ploughing (P). A single‐disc drill was used in the H8‐10 and D treatments and a traditional seed drill in the P treatment. Measurements were carried out in 2004–05 and 2005–06 and winter wheat was grown in both years (first and second year winter wheat). Shoot and root growth was followed during the growing seasons using spectral reflectance and mini‐rhizotron measurements, respectively. A range of soil physical properties were measured. We found decreased early season shoot and root growth with decreasing tillage intensity. Differences diminished later in the growing season, although significant treatment effects were observed throughout the growing season for the second year winter wheat. The formerly ploughed layer in the D and H8‐10 treatments was noticeably compacted as indicated by increases in both penetration resistance and bulk density. Nitrate leaching increased with decreasing tillage intensity for the first year winter wheat at Foulum. In general ploughing resulted in the highest grain yields. This study highlights the important interaction between soil structure and crop growth dynamics.  相似文献   

17.
Computer simulation was used for predictive analysis of the effects of weather and soil type on crop yield in the U.S.crop insurance program.The Environmental Policy Integrated Climate (EPIC) model was modified to include hail weather events,which completed the modifications necessary to simulate the four most frequent causes of crop yield loss (hail,excessive wet,excessive cold,and excessive dry) associated with soil type in Kansas,USA.At the region level,per hectare yields were simulated for corn,wheat,soybean,and sorghum.We concluded that it was possible to predict crop yields through computer simulation with greater than 93% accuracy.The hail damage model test indicated EPIC could predict hail-soil-induced yield losses reasonably well (R2 > 0.6).The investigation of soil type influence on dryland sorghum and wheat production indicated that Wymore silty clay loam soil and Kenoma silt loam produced the highest sorghum yields statistically;Kuma silt loam,Roxbury silt loam,Crete silty clay loam,and Woodson silt soils produced the second highest sorghum yields statistically;and Richfiled silt loam,Wells loam,and Canadian sandy loam produced the lowest sorghum yields.By contrast,wheat production showed less sensitivity to soil type variation.The less sensitive response of wheat yields to the soil type could be largely due to the unconsidered small-scale variability of soil features.  相似文献   

18.
Cereal cropping productivity in the Indo‐Gangetic Plain (IGP) of India is declining, which may be overcome by diversification, alternate crop establishment methods and mulching. This study was conducted to determine whether no‐till flat (NTF), permanent raised beds (PRB) and nontraditional ex situ mulching would improve crop and water productivity, economic profitability and soil biological properties in an irrigated maize (Zea mays)–wheat (Triticum aestivum) system (MWS). NTF systems produced 10% higher economic net returns compared with PRBs. Non‐traditional mulching (Sesbania, Jatropha and Brassica) increased yields by >10% and net returns by >12% compared with no‐mulch. The water saving in PRBs compared with NTF systems was 79, 94 and 173 mm/ha in maize, wheat and MWS, respectively. PRBs saved 29.2% of irrigation water and improved the MWS irrigation water productivity (WPI) by 24.5% over NTF. On average, mulching saved 23.8 mm/ha irrigation water over no‐mulch and improved WPI by 12.0%. PRBs with ex situ mulching produced wheat and maize equivalent system yields lower than NTF but improved WPI and soil biological properties. Jatropha and Sesbania mulching improved yield, water saving, WPI and system profitability. In limited irrigation and no crop residue availability conditions, Sesbania, Jatropha and Brassica vegetation material have potential applications for ex situ mulching under PRBs for water saving and NTF for productivity.  相似文献   

19.
An experiment was conducted to evaluate the effects of tillage and residue incorporation on soil properties and yields of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) in rotation for 4 years on a silty clay loam of an Aquic Hapludoll with natural water table fluctuating between 0.05 and 0.97 m depth The rice experiment was laid out in split plot design with four levels of tillage, viz. conventional puddling (CP), puddling by four passes of rotavator (PR), reduced puddling by two passes of rotavator (ReP), and direct seeding without puddling (DSWP) and two levels of residue, viz. residue incorporation (RI) and residue removal (RR) in four replications. The treatments for wheat were zero tillage (ZT) and conventional tillage (CT) with RI and RR superimposed over the plots of rice. Tillage for rice increased puddling index and bulk density (BD) over the years. The increase was significantly higher in CP and PR than in ReP. In wheat season, BD was higher under ZT than under CT but the differences were not significant. Puddling decreased saturated hydraulic conductivity with time, which became significantly lower in CP and PR in the fourth year than in ReP in the first year. Infiltration rate (IR) also decreased with time and was lowest in CP and PR. In wheat season, IR was at par under ZT and CT. Rice yield in PR was maximum and at par with that in ReP. But wheat yield was lowest in PR and highest in DSWP, and was at par in DSWP and ReP. Thus, rice yields were optimum under ReP, in which changes in soil properties were least, and wheat yields were optimum both under ZT and CT in the DSWP and ReP plots of rice under shallow water table conditions of the silty clay loam.  相似文献   

20.
Soil quality in rice (Oryza sativa L.)–wheat (Triticum aestivum L.) cropping systems is governed primarily by the tillage practices used to fulfill the contrasting soil physical and hydrological requirements of the two crops. The objective of this study was to develop a soil quality index (SQI) based on bulk density (BD), penetration resistance (PR), water stable aggregates (WSA) and soil organic matter (OM) to evaluate this important cropping system on a Vertisol in India. Regression analysis between crop yield and SQI values for various tillage and crop residue management treatments indicated SQI values of 0.84–0.92, 0.88–0.93 and 0.86–0.92 were optimum for rice, wheat and the combined system (rice + wheat), respectively. The maximum yields for rice and wheat were 5806 and 1825 kg ha−1 occurred at SQI values of 0.85 and 0.99, respectively. Using zero tillage (ZT) for wheat had a positive effect on soil quality regardless of the treatments used for rice. Regression analyses to predict sustainability of the various tillage and crop residue treatments showed that as puddling intensity for rice increased, sustainability without returning crop residues decreased from 6 to 1 years. When residue was returned, the time for sustainable productivity increased from 6 to 15 years for direct seeded rice, 5 to 11 years with low-intensity puddling (P1) and 1 to 8 years for high-intensity (P2) puddling. For sustainability and productivity, the best practice for this or similar Vertisols in India would be direct seeding of rice with conventional tillage and residues returned.  相似文献   

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