Conservation Tillage Treatments Research Articles

Analyzing the Trade-Offs between Soil Health Enhancement, Carbon Sequestration, and Productivity in Central India’s Black Soil through Conservation Agriculture

The impact of conservation tillage (CST) practices on soil properties, carbon sequestration and yield sustainability over short, medium, and long durations remain insufficiently understood, especially in semiarid Central India. Therefore, our objective was to investigate the effects and optimal duration of CST adoption for enhancing soil properties, carbon sequestration, and sustainable yields. We conducted a study in farmers’ fields in the Akola district of Central India, where CST had been practised for 4 to 15 years, within a soybean + pigeon pea–chickpea cropping sequence. Our findings revealed significant (p < 0.05) improvements in soil physical properties with short-term CST practices (4 to 6 years), alongside increasing availability of nitrogen and phosphorus, with longer durations of CST implementation (10 to 15 years). The lowest soil organic carbon (SOC) was observed in conventional tillage (CT_y), while all CST practices increased SOC content over CT_y, ranging from 22.2 to 38.4%. Further, experimental soil dominated passive C pools (Cfrac3 + Cfrac4). Consequently, long-term CST practices facilitated positive C sequestration rates, contrasting with negative or minimal sequestration observed in CT_y and short-term CST treatments. However, compared to CST, CT_y demonstrated higher soybean equivalent yields and comparable chickpea equivalent yields mainly due to delayed germinations induced by lower soil temperatures in CST plots. We conclude that integrating site-specific characteristics, management practices, and regional climate conditions into conservation agriculture frameworks maximizes efficacy and ensures sustainable productivity. These findings help optimize agricultural practices considering potential yield losses or minimal changes despite implementing CST.

Effect of Tillage and Precision Nitrogen Management Practices on N Uptake and Nutrient Use Efficiency (NUE) in Wheat in Western Uttar Pradesh, India

At the Crop Research Center of Sardar Vallabhbhai Patel University of Agriculture & Technology, Meerut, (U.P.), during the rabi seasons of 2021–22 and 2022–23, an investigation titled " Effect of tillage and precision nitrogen management practices on N uptake and Nutrient Use Efficiency (NUE) in wheat in western UP " was conducted. The experiment was carried out using a split plot design with three replications. The treatments included four precise nitrogen treatments (N1-Control, N2-State recommendations, N3- Leaf Colour Chart (LCC) based nitrogen Application, and N4- Soil Plant Anaylsis Development (SPAD) meter based treatments) as sub plot treatments, and three conservation tillage treatments (C1- Conventional tillage, C2- Reduced tillage, and C3- Furrow irrigated raised bed (FIRB)} as main plots. The soil of the experimental site was sandy loam having low organic matter (0.43%), low in available nitrogen, low in available phosphorus and high in available potassium. The maximum N uptake and NUE was recorded under furrow irrigated raised beds plots during both the years. The maximum total N uptake and NUE was recorded under SPAD and was at par with LCC treatments.

The impact of conservation tillage intensities on mean yields and yield risk

Understanding the productivity and production risk effects of conservation tillage practices are important so that growers can make better decisions about tillage systems appropriate for their farm operations. This study investigates the mean yield and yield risk effects of conservation tillage practices with varying levels of tillage intensity and timing. Long-term field trial data for corn (Zea mays, L.) and soybeans (Glycine max, L. Merr.) in the North Carolina Piedmont, together with moment-based regression models, were used to achieve the objective of the study. Our empirical analysis suggests that conservation tillage treatments (with lower tillage intensities and higher residue levels) consistently have higher mean yields than conventional tillage practices in the sandy loam soils of the North Carolina Piedmont. However, we find that conservation tillage practices with lower intensities (and higher residue levels) do not generally have a consistent statistically significant risk reducing effect based on the higher-order moments of the yield distribution (e.g., variance, skewness, and kurtosis). This indicates that conservation tillage does not consistently result in statistically lower production risk relative to conventional tillage methods.

Changes in Soil Properties and Crop Yield under Sustainable Conservation Tillage Systems in Spring Wheat Agroecosystems

The cultivated soils in several semi-arid areas have very low organic matter due to climatic constraints that limit primary crop yield. Conservation tillage systems, outlined here as no tillage, no tillage with straw return and straw incorporation into the field, have been accepted as capable systems that preserve soil’s resources and sustain soil productivity. However, in semi-arid climates, there is presently no knowledge about the influence of different conservation tillage techniques on soil’s physical, chemical and biological properties at different soil depths in spring wheat fields and only little information about spring wheat yield in these management systems. Therefore, the present study was carried out with the objective of examining the impact of conservation tillage systems on soil properties (physical, chemical and biological) and spring wheat yield. The three conservation tillage treatments consisted of no tillage system (NT), wheat stubble return with no tillage (NTS) and straw incorporation with conventional tillage (CTS), as well as one conventional tillage (CT) control treatment, which were evaluated under randomized complete block design with three replications. The three conservation tillage treatments were compared with the conventional tillage control. Conservation tillage significantly increased the bulk density, gravimetric water content, water storage, hydraulic conductivity and soil aggregates and decreased the pore space and soil temperature compared to CT; however, no significant difference was found in the case of field capacity. Soil chemical properties in the 0–40 cm soil layer increased with conservation tillage compared to CT. Conservation tillage also notably increased the soil microbial counts, urease, alkaline phosphatase, invertase, cellulase and catalase activities relative to CT. Microbial biomasses (carbon and nitrogen) and wheat yield significantly elevated under conservation tillage compared to CT. Therefore, conservation tillage could significantly improve soil properties and maintain wheat yield for the research zone.

Can a Change in Agriculture Management Practice Improve Soil Physical Properties

Soil conventional tillage has been associated with deterioration of its characteristics, while organic farming has been promoted as an approach to conserve a favorable soil environment. With the interest in nominating the tillage strategies without ploughing for maintaining long-term soil quality and subsequently increasing yields, this study set to identify if and how conservation tillage practices in organic management (OM) do improve soil physical properties compared to conventional management (CM). This study was conducted on matched field pairs in Baden-Württemberg, Germany. The conservation tillage treatment effects of OM (superficial tillage using chisel at 10 cm depth) was compared with conventional tillage practices CM (mouldboard ploughing at 30 cm depth). The field pairs were homogenous in most respects that would reflect tillage impacts. Measurements included soil infiltration capacity, saturated hydraulic conductivity, penetration resistance, and effective bulk density. Infiltration rate, measured using a hood infiltrometer at 10 parcels, was computed using Wooding’s analytical method, while Gardner’s equation was used to calculate the saturated hydraulic conductivity (Ks). The steady infiltration rate qs (h) was two times higher under OM than under CM with an average of 624 mm/h and 303 mm/h, respectively. Penetration resistances of OM were lower than under CM irrespective of the clay content. The degree of compactness (effective bulk density) was greater under CM than OM. That small change in soil compactness affects the water infiltration rate and the hydraulic properties rather than intrinsic soil matrix such as texture. Numerical model Hydrus-1D results were more representative for simulating the soil water transfer and hydraulic parameters under tillage changes.

Effects of Plasticulture and Conservation Tillage on Nematode Assemblage and Their Relationships with Nitrous Oxide Emission following a Winter Cover Cropping and Vegetable Production System

Agriculture production emits significant amounts of nitrous oxide (N2O), a greenhouse gas with high global warming potential. The objectives of this study were to examine whether different husbandry practices (tillage and plasticulture) following winter cover cropping would influence soil food web structure and whether a change in the soil community could help mitigate N2O emission in vegetable plantings. Three consecutive field trials were conducted. A winter cover crop mix of forage radish (Raphanus sativus), crimson clover (Trifolium incarnatum) and cereal rye (Secale cereale) were planted in all plots. Winter cover crop was terminated by flail mowing followed by (1) conventional till without surface residues [Bare Ground (BG)], (2) conventional till with black plastic mulch (BP) without surface residues, (3) strip-till (ST) with partial surface residues, or (4) no-till (NT) with surface residues. The cash crop planted subsequently were eggplant (Solanum melongena) in 2012 and 2014 and sweet corn (Zea mays) in 2013. The soil food web structure was consistently disturbed in the BP compared to other treatments as indicated by a reduction in the abundance of predatory nematodes in 2012 and 2014, and nematode maturity index in 2013 in BP. Changes in soil food web structure in the conservation tillage (NT or ST) treatments based on the weight abundance of nematode community analysis were not consistent and did not improve over the 3-year study; but were consistently improved based on functional metabolic footprint calculation at termination of cover crops of 2013 and 2014. None-the-less, the N2O emissions increased as the abundance of fungivorous nematodes increased during all three trials. It was also found that improved soil food web structure [higher abundance of omnivorous in 2012 or predatory nematodes in 2013 and 2014, and structure index (SI) in all 3 years] reduced N2O emissions. These findings suggested that proper soil husbandry practices following winter cover cropping could mitigate N2O emissions over time.

Depthwise variation in selected soil properties as influenced by tillage and residue management in sandy loam soil of North-West Himalayas, India

The present study aimed to determine the effect of varying tillage and residue management in a sandy loam soil under maize (Zea mays L.)-wheat (Triticum aestivum L.) sequence. The research was carried out at ICAR- Indian Institute of Soil and Water Conservation, Research Centre, Chandigarh, research farm, located at Panchkula, Haryana, in maize (kharif)-wheat (rabi) cropping sequence during 2009–2017. Six treatments implemented were Conventional tillage (CT); Deep tillage once in three years (DT); Conventional tillage with integrated nutrient management (CT-INM); Conventional tillage with brown manuring in maize + cowpea (1:2) and wheat + pea (4:1) ratio (CT-BM); Conservation tillage (CST) ; Conservation tillage with brown manuring (CST-BM). The compaction level attained under conservation tillage based systems were lower than the corresponding levels in the conventional tillage control. The highest percentage of macro aggregates was found in CST-BM treatment (48%), followed by CST (45%) and CT, DT and CT-INM recorded much lesser macro aggregate (29.3, 28 and 31%). Conventional tillage (CT) reduced macroaggregates with a concomitant increase in microaggregates (<0.25 mm) percentage. The mean soil moisture percentage average in surface (0–15 cm) and sub surface soil (15–30 cm) were found to be higher under DT, CST and CST-BM treatments over CT and CT-INM treatments. In general, the soil moisture was found to be proportional to the amount of biomass added under various treatments. The mean soil available nitrogen were 15.4% and 17.5% higher under CT-BM and CST-BM treatments respectively, over the control (CT).

Cotton Weed Management Systems in Conventional and Conservation Tillage

Weed management trials were established near Lubbock, TX in 2017 and 2018 to compare systems in both conventional and conservation tillage. Four herbicide systems were included for both the conventional and conservation tillage. Conventional tillage treatments included trifluralin preplant incorporated (PPI) followed by (fb) no preemergence (PRE) fb dicamba + glyphosate + acetochlor early postemergence (EPOST) fb dicamba + glyphosate midpostemergence (MPOST), trifluralin PPI fb prometryn PRE fb dicamba + glyphosate EPOST fb dicamba + glyphosate + acetochlor MPOST, no PPI fb prometryn PRE fb dicamba + glyphosate EPOST fb dicamba + glyphosate + acetochlor MPOST, trifluralin PPI fb prometryn PRE fb glyphosate EPOST fb glyphosate + acetochlor MPOST. Conservation tillage treatments included dicamba + glyphosate early preplant (EPP) fb paraquat + prometryn PRE fb dicamba + glyphosate EPOST fb dicamba + glyphosate MPOST, dicamba + glyphosate + flumioxazin EPP fb paraquat + prometryn PRE fb dicamba + glyphosate EPOST fb dicamba + glyphosate MPOST, glyphosate EPP fb dicamba + prometryn fb dicamba + glyphosate EPOST fb dicamba + glyphosate MPOST, no EPP fb dicamba + prometryn fb dicamba + glyphosate EPOST fb dicamba + glyphosate MPOST. Visual weed control for Russian thistle, kochia, and Palmer amaranth was recorded at cotton planting and 14 days after planting. Palmer amaranth control was recorded at 14 and 28 days after the EPOST and MPOST treatments. Effective season-long control of Palmer amaranth (>98%) was achieved using various dicamba-based herbicide systems in both conventional and conservation tillage. Glyphosate-based herbicide systems controlled Palmer amaranth <53% in 2017 and <84% in 2018 due to the number of glyphosate-resistant weeds present. All dicamba treatments controlled Palmer amaranth >83% in 2017 and >98% in 2018.

Interactive Effects of Residue and Tillage Methods on Growth, Yield and Yield Components of Melon

Field experiments were conducted to investigate the effects of residue and tillage on growth and yield of melon. Tillage treatments included conventional tillage (using a moldboard plough and two passes with a disk harrow), minimum tillage (one pass with a disk harrow), and no tillage (NT). Residue treatments included the application of 0%, 30% and 60% residue. Yield and yield components were obtained for all treatments. Tillage significantly affected yield and its components (P ≤ 0.05). The maximum FWPP (2.678 kg), NFPP (6.799), D (18.49 cm), L (45.93 cm), S (12.51%) and RUE (2.470) and yield (16.17 t/ha) were recorded in the conventional tillage treatment. Also, maximum FWPP (2.192 kg), NFPP (5.353), D (16.66 cm), L (39.52 cm) and yield (12.83 t/ha) were observed in the 30% residue treatment. In terms of the interaction effects, maximum FWPP (2.850 kg), NFPP (6.790), D (20.71 cm), L (53.53 cm) and yield (17.09 t/ha) were obtained in the conventional tillage + 30% residue treatment. Therefore, the use of a moldboard plough followed by two passes with a disk harrow, in concert with 30% residue treatment, were maximizing the yield Almost all growth indicators had the optimum values in the conservation tillage treatments.

The Effect of Different Tillage Systems, Nitrogen Fertilizer and Mycorrhiza on Mung Bean (Vigna radiata) Production and Energy Indices

ABSTRACT Concerns about fossil fuel conservation and greenhouse gas emissions have oriented higher research on energy balance in crop production systems. The purpose of this study was to investigate the yield and energy indices of mung bean crops cultivated in Darehshahr research fields in two years (2017 and 2018). The experiment was conducted in a split randomized complete block design with three replications. Treatments consisted of tillage at three levels as conventional, conservation and no tillage system in the main plot, nitrogen fertilizer at four levels (control (without fertilizer), 33%, 66% and 100% of recommended fertilizer in sub plot, and mycorrhizal fungi (Glomus mosse) at two levels (control (no application) and application) in sub-sub-plot. During two years of study, energy consumption data for crop production and its operations were recorded. Our results indicated that the highest grain yield was observed from the conservation tillage treatment as 2842 kg ha−1. The highest input energy was recorded for conventional tillage system and application of 100% N fertilizer. However, the highest energy output was obtained from the conservation tillage treatment with 66% nitrogen. The calculation of energy indices showed that the no-tillage system outperformed the other systems in terms of energy efficiency (7%) and energy productivity (0.8 kg MJ−1). For the conventional tillage system, energy efficiency (4.2%) and energy productivity (0.42%) were the lowest energy indices. Increasing nitrogen levels from 0.0 to 100%, reduced energy efficiency and energy productivity by 18.3% and 8.2%, respectively.

Potential of conservation agriculture modules for energy conservation and sustainability of rice-based production systems of Indo-Gangetic Plain region

Rice-based cropping systems are the most energy-intensive production systems in South Asia. Sustainability of the rice-based cropping systems is nowadays questioned with declining natural resource base, soil degradation, environmental pollution, and declining factor productivity. As a consequence, the search for energy and resource conservation agro-techniques is increasing for sustainable and cleaner production. Conservation agriculture (CA) practices have been recommended for resource conservation, soil health restoration and sustaining crop productivity. The present study aimed to assess the different CA modules in rice-based cropping systems for energy conservation, energy productivity, and to define energy-economic relations. A field experiment consisted of four different tillage-based crop establishment practices (puddled-transplanted rice followed by (fb) conventional-till maize/wheat (CTTPR-CT), non-puddled transplanted rice fb zero-till maize/wheat (NPTPR-ZT), zero-till transplanted rice fb zero-till maize/wheat (ZTTPR-ZT), zero-till direct-seeded rice fb zero-till maize/wheat (ZTDSR-ZT)), with two residue management treatments (residue removal, residue retention) in rice–wheat and rice–maize rotations were evaluated for energy budgeting and energy-economic relations. Conservation-tillage treatments (NPTPR-ZT, ZTTPR-ZT, and ZTDSR-ZT) reduced the energy requirements over conventional tillage treatments, with the greater reduction in ZTTPR-ZT and ZTDSR-ZT treatments. Savings of energy in conservation-tillage treatments were attributed to reduced energy use in land preparation (69–100%) and irrigation (23–27%), which consumed a large amount of fuel energy. Conservation-tillage treatments increased grain and straw/stover yields of crops, eventually increased the output energy (6–16%), net energy (14–26%), energy ratio (25–33%), and energy productivity (23–34%) as compared with CTTPR-CT. For these energy parameters, the treatment order was ZTDSR-ZT ≥ ZTTPR-ZT > NPTPR-ZT > CTTPR-CT (p < 0.05). Crop residue retention reduced net energy, energy ratio, and energy productivity when compared with residue removal. Our results of energy-economic relations favored the “conservative hypothesis,” which envisages that energy and monetary investments are not essentially the determinants of crop productivity. Thus, zero tillage-based crop establishments (ZTTPR-ZT, ZTDSR-ZT) in rice-based production systems could be the sustainable alternative to conventional tillage-based agriculture (CTTPR-CT) as they conserved non-renewable energy sources, reduced water requirement, and increased crop productivity.

Effect of Reversal of Conservation Tillage on Soil Nutrient Availability and Crop Nutrient Uptake in Soybean in the Vertisols of Central India

Effect of conservation tillage on crop performance and soil properties has been studied extensively under different agro-climatic situations. However, the impact of reversal from conservation tillage to conventional tillage on crop growth and soil nutrient release is rarely addressed. Thus, this study was conducted by converting half of the eight years old conservation tillage experiment to the conventional one with a similar level of residue return to compare the effect on soil nutrient availability and nutrient uptake in soybean crops in the Vertisols of Central India. The conservation tillage treatments included no-tillage (NT) and reduced tillage (RT) with 100% NPK (T1), 100% NPK + farmyard manure (FYM) at 1.0 Mg-carbon (C)/ha (T2), and 100% NPK + FYM at 2.0 Mg-C/ha (T3). After eight years of the experiment, the RT and NT treatments were subjected to conventional tillage, and thus the tillage treatments were RT-CT, RT, NT, and NT-CT. After tillage reversal for three growing seasons, soybean yield and nutrient uptake (N, P, K) got significantly influenced by the tillage and nutrient management. Averaged across nutrient treatments, NT showed highest soil organic carbon (SOC) content (8.4 g/kg) in the surface 0–5 cm layer. However, at 5–15 cm depth, the SOC was greater in the RT-CT treatment by 14% over RT and by 5% in the NT-CT treatment over NT. The soil nutrient availability (N and P) was not significantly (p &gt; 0.05) affected by the interaction effect of tillage and nutrient on the surface soil layer (0–5 cm). Interaction effect of tillage and nutrient was significant on available P content at 5–15 cm soil depth. In contrast to N, soil available P relatively increased with reversal of tillage in both NT and RT. Tillage reversal (NT-CT, RT-CT) and RT had significantly higher available potassium than NT in 0–5 and 5–15 cm soil layers. Among the treatments, NT-CT-T3 showed significantly higher seed N (85.49 kg/ha), P (10.05 kg/ha), and K (24.51 kg/ha) uptake in soybean. The study indicates conventional tillage with residue returns and integrated nutrient management could be a feasible alternative to overcome the limitations of no-till farming in the deep black Vertisols of Central India.

Simulating the effects of conventional versus conservation tillage on soil water, nitrogen dynamics, and yield of winter wheat with RZWQM2

The movement and distribution of the soil water and nitrogen are significantly influenced by tillage management. However, the dynamics of soil water and nitrogen due to changes in tillage and surface residue cover can be difficult to characterize due to limitations in field experimentation. The objective of this study was to quantify the differences in the soil water and nitrogen balance in the 0–100 cm soil profile, winter wheat (Triticum aestivum L.) yield, water productivity (WP) and nitrogen use efficiency (NUE) that occur when conventional tillage (CT) was changed to four types of conservation tillage treatments (no-tillage [NT], subsoiling tillage [ST], no-tillage with straw [NS] and subsoiling tillage with straw [SS]). Experimental data from 2011 to 2016 collected in Henan province, China on a sandy loam soil was used to calibrate and validate the Root Zone Water Quality Model (RZWQM2). Then the model was used to simulate four tillage systems (NT, NS, ST, SS) that were then compared with CT. The agreement index (d) between simulated and measured soil water content, soil nitrate concentration, and grain yield ranged between 0.71 and 0.93. The root means square error (RMSE) of the soil water content and nitrate concentration was in the range 0.02–0.03 cm cm−1and 5.5–10.3 mg kg−1, respectively. When CT was converted to NT from 2011 to 2016, the model simulated a 9.1 % reduction in annual water loss and a 55.6 % decrease in nitrogen leaching loss and simulated significant increase in average grain yield, WP and NUE. Replacing CT with NT appears to be the best of the four alternative conservation tillage conversion strategies in Henan Province of China.

Effect of conservation tillage on crop productivity and nitrogen use efficiency

The hypothesis that the optimal nitrogen rate for crop yield and nitrogen use efficiency (NUE) are affected by tillage treatment, crop type and soil properties (type) was evaluated by an experiment which include five different tillage treatments (CT-conventional, SS-subsoiling, CH-chiselling, DH-disk-harrowing and NT-no-till), three levels of nitrogen rates (N1-reduced, N2-optimal and N3-luxury), on two different soil types (Stagnosol and Gleysol) and with two different crops (maize and winter wheat). Soil and plant samples were taken from the first and second year in the second four-year crop rotation cycle. The highest value of soil compaction (ρb-bulk density and PD-packing density) as well as the lowest soil total porosity (P) was found, on average for all tillage treatments, on Gleysol in both experimental year in the root zone (20–40 cm). At all depths the highest values of ρb and PD were recorded for DH treatment on Gleysol and for soil porosity for NT treatment on Stagnosol. Grain yields, biomass, and harvest index of maize and winter wheat on both soil type respond positively to conservation tillage treatment, but with different significations. Soil cover crop residues were significantly affected by soil treatment and nitrogen fertilization (P < 0.01), and decreasing in the following order: NT > CH > SS > DH > CT on both soil types. The average NUE in general decreased successively under N1, N2 and N3 with respective NUEs on Stagnosol 58.5, 49.5 and 36.0 kg kg−1 for maize and 59.9, 45.3 and 35.9 kg kg−1 for winter wheat. Corresponding values on Gleysol were 78.5, 69.4, 52.0 kg kg−1 and 46.3, 51.3, 44.0 kg kg−1. The grain and biomass of winter wheat increased from N1 to N2, whereas from N2 to N3 they decreased, increased or remained almost the same depending on the tillage system and soil type. The effect of all the investigated tillage treatments on NUE and crop yield was variable depending on particular tillage system, crop type and soil type. The results indicate that, from the NUE and crop yield viewpoints, the N2 and N3 nitrogen rates are respectively most and least suitable on both soil types, depending on soil treatment. Irrespective of the nitrogen application rate and tillage treatments, the NUEs were the most comparable treatments higher in the more productive Gleysol (32.7–92.5 kg kg−1) than in Stagnosol (26.4-76.7 kg kg−1).

Distribution of soil aggregates and organic carbon in deep soil under long-term conservation tillage with residual retention in dryland

To ascertain the effects of long-term conservation tillage and residue retention on soil organic carbon (SOC) content and aggregate distribution in a deep soil (>20-cm depth) in a dryland environment, this paper analyzed the SOC and aggregate distribution in soil, and the aggregate-associated organic carbon (OC) and SOC physical fractions. Conservation tillage (reduced tillage with residue incorporated (RT) and no-tillage with residue mulch (NT)) significantly increased SOC sequestration and soil aggregation in deep soil compared with conventional tillage with residue removal (CT). Compared with CT, RT significantly increased the proportion of small macroaggregates by 23%–81% in the 10–80 cm layer, and the OC content in small macroaggregates by 1%–58% in the 0–80 cm layer. RT significantly increased (by 24%–90%) the OC content in mineral-SOC within small macroaggregates in the 0–60 cm layer, while there was a 23%–80% increase in the 0–40 cm layer with NT. These results indicated that: (1) conservation tillage treatments are beneficial for soil aggregation and SOC sequestration in a deep soil in a dryland environment; and (2) the SOC in mineral-associated OC plays important roles in soil aggregation and SOC sequestration. In conclusion, RT with NT is recommended as an agricultural management tool in dryland soils because of its role in improving soil aggregation and SOC sequestration.

Environmental sustainability and water productivity on conservation tillage of irrigated maize in red brown terrace soil of Bangladesh

Abstract Conservation tillage (CA) is an option for maintaining soil health and the surrounding environment for intensive agriculture, especially on the tropical climate. A three years lengthy research experiment was performed in arid climate from 2014 to 2016 at Bangladesh Agricultural Research Institute (BARI) to evaluate the effect of conservation tillage approaches on environmental sustainability and water productivity of irrigated maize cultivation. The conservation tillage practices (Zero tillage-ZT and Minimum tillage-MT) are evaluated in comparison to the traditional farmer’s practices. Amongst these, the treatment combination having MT with optimum irrigation best suits for cost-effective sustainable technique in maize cultivation without compromising with the yield at the dry season in the red brown terrace soil of Bangladesh. This combination of CA treatment is environment-friendly for maize cultivation as the treatment combination consumes the lowest amount of fuel (29.70 L/ha) for tilling purposes and required fewer water resources (only 2 time irrigation) for irrigation purposes and thus reduces the amount of carbon dioxide and other emitted toxic gaseous molecules to the surrounding environment. Therefore, MT with optimum irrigation is evaluated as the best options for continuous maize cultivation in the red brown terrace soil without any yield penalty.

Effects of conservation tillage systems on soil physical changes and crop yields in a wheat–oilseed rape rotation

Five conservation tillage treatments were applied to an alternating rotation of wheat (<i>Triticum aestivum</i> L.) and oilseed rape (<i>Brassica napus</i> L.) within neighboring clay and clay loam fields in the United Kingdom over three cropping seasons (2013 to 2016) with the objective of determining how the treatments affect soil physical characteristics, weed control, and crop yields. The conservation tillage systems included a relatively disruptive “Farm System” with cultivation to a depth of 200 mm, three intermediate treatments, and a “Low Disruption” treatment with cultivation to a depth of 25 to 100 mm. The disruptive Farm System showed the greatest increase in soil porosity immediately after tillage and resulted in higher wheat and oilseed rape plant counts than the other treatments. Each tillage treatment resulted in mean soil penetration resistances below 2.5 MPa, although a tillage treatment with tine depth to width ratio of 7.5:1 resulted in a higher resistance (2.14 MPa) at 150 to 200 mm than three other treatments (1.36 to 1.67 MPa) in year 1. Despite the above differences, the five tillage systems resulted in statistically similar wheat and oilseed rape yields, except when there was a delay in applying one treatment to the oilseed rape in year 3. In the first two years, the yields of wheat in the clay (9.7 to 10.6 t ha⁻¹) and the clay loam field (11.0 to 11.6 t ha⁻¹) were similar to yields on other commercial farms. However, in year 3, the wheat yield on the clay soil declined to 8.7 to 9.5 t ha⁻¹. Some of this is a result of low levels of solar radiation in 2016, but the levels of blackgrass (<i>Alopecurus myosuroides</i> Huds.) increased from 8.2% to 16.0%. There was no statistically significant difference between the capacity of the conservation till-age treatments to control blackgrass on the clay soil, indicating that other measures are needed to control this competitive weed.

Comprehensive assessment of soil fertility characteristics under different long-term conservation tillages of wheat field in Weibei Highland, China.

Soil fertility properties described by four physical indices and seven chemical indices in the 10-year long-term experiment of wheat fields in Weibei Highland were used to investigate the cumulative effect of 11 soil indices under six long-term conservation tillage treatments. The principal component analysis was performed to comprehensively evaluate the cumulative effect of soil fertility under different tillage treatments, so as to provide scientific basis for soil sustainable utilization and management in Weibei Highland. The results showed that, compared with continuous conventional tillage (CT/CT), soil bulk density by no-tillage/subsoiling rotational tillage (NT/ST), subsoiling/conventional tillage rotational tillage (ST/CT) and conventional tillage/no-tillage rotational tillage (CT/NT) decreased by 6.6%, 5.9% and 6.6%, respectively, and no significant difference was found between continuous no-tillage (NT/NT) and CT/CT. NT/NT had the highest content of >0.25 mm mechanical stable aggregate, and no-tillage/subsoiling rotational tillage (NT/ST) had the highest content of >0.25 mm water stable aggregate. Compared with CT/CT, the mechanical stable aggregate contents under other five tillage treatments increased by 1.7%-10.1%, soil organic matter increased by 0.6%-11.2%, and the contents of nitrogen, phosphorus, and potassium contents also increased. By principal component analysis, 11 soil indices were divided into two principal components to comprehensively characterize soil quality. The contribution rate of the first principal component was 75.5%, where the major contributors were soil organic matter, water stable aggregate, total nitrogen, total phosphorus, total potassium, alkaline hydrolysis nitrogen, available phosphorus, available potassium, bulk density and soil porosity. The contribution rate of the second principal component was 13.2%, where the major contributor was mechanical stable aggregate. Together, those two principal components accounted for 88.6% of the original variables. The soil fertility performance was in the sequence of NT/ST>ST/CT>CT/NT>NT/NT>ST/ST>CT/CT after gradually accumulating the effects of long-term conservation tillage. NT/ST was the most appropriate tillage patterns for the wheat fields in Weibei Highland, due to the resulting balanced and high-quality soil environment.

Evaluation of the performance of the EPIC model for yield and biomass simulation under conservation systems in Cambodia

Limited field studies have been performed to evaluate the impacts of conservation agriculture (CA) on crop yields and soil organic carbon sequestration in tropical conditions. In this study, we used the Environmental Policy Integrated Climate (EPIC) model to evaluate the impact of CA and conservation tillage (CT) on crop yields in tropical conditions for unique upland rice, soybean, and cassava cropping systems in Cambodia. New crop parameters were developed and tested for cassava, sesame, banana, sunn hemp, stylo, and congo grass. The results show that EPIC successfully replicated crop yields of soybean, upland rice, maize, and cassava based on R2 statistics ranging from 0.62 to 0.88 and percent bias (PBIAS) values ≤10%. However, it cannot be concluded that the model can accurately capture the biomass for all the individual crops due to limitations in the observed biomass data. The cassava and maize biomass were simulated satisfactorily, resulting in R2 values of 0.81 and 0.75, respectively. However, the computed PBIAS for the biomass estimates of the two crops were >25%. In contrast, the predicted rice and soybean biomass met PBIAS criteria (≤23%) but resulted in weak R2 statistics of ≤0.20, indicating inaccurate replications of the measured biomass. Similarly, the cover crop mean biomass and PBIAS statistics were acceptable but the R2 values were not. Overall, the model tended to overestimate the measured crop biomass. No significant difference was found in the simulated crop yields between the CA and CT treatments. However, the predicted rice and soybean results reflect an increased yield trend over time for the CA treatments, versus no discernible trend for the cassava and maize yields.

Crop establishment with conservation tillage and crop residue retention in rice-based cropping systems of Eastern India: yield advantage and economic benefit

Continuous practice of tillage intensive puddled rice-based systems in South Asia has developed serious issues related to soil health and production sustainability. This has exaggerated the need for sustainable alternatives. Here, the impact of four tillage cum crop establishment practices [conventional puddled transplanted rice followed by conventional till maize/wheat (CTTPR-CT), non-puddled transplanted rice followed by zero-till maize/wheat (NPTPR-ZT), zero-till transplanted rice followed by zero-till maize/wheat (ZTTPR-ZT), zero-till direct seeded rice followed by zero-till maize/wheat (ZTDSR-ZT)], two residue management [residue removal, residue retention (~ 33.0%)] and two rice-based rotations (rice–wheat, rice–maize) on crop performance, system productivity, and production economics were evaluated. At 4th and 5th year of rotation, complete zero-tillage-based crop establishment (ZTDSR-ZT, ZTTPR-ZT) enhanced the grain yield of rice (9.3–20.6%), wheat (18.4–22.6%), and maize (10.8–11.8%) over CTTPR-CT, whereas yield advantage in NPTPR-ZT was marginal for all the crops. The higher grain yield of rice and wheat in ZTDSR-ZT and ZTTPR-ZT treatments was mainly attributed to higher tiller production (rice 11.5–23.2%; wheat 29.5–34.9%). Likewise, the higher aboveground biomass, cob length, cob weight, and grains weight cob−1 led to higher maize yield in conservation tillage treatments (NPTPR-ZT, ZTDSR-ZT, and ZTTPR-ZT). Retention of crop residue improved (p < 0.05) the yield of all crops being higher in maize (6.9–10.3%) followed by wheat (5.3–10.5%). The reduced cost of cultivation and higher return from produce in ZTDSR-ZT, ZTTPR-ZT, and NPTPR-ZT enhanced the net income by INR 48164, 35800, 25632, respectively, over CTTPR-CT. Thus, zero-tillage-based crop establishments with crop residue retention were found as potential alternative for improving crop productivity, profitability and sustainability of rice-based production systems.