Tillage Levels Research Articles

Effects of cover crop and tillage management practices on in situ and ex situ water infiltration parameters

ABSTRACT Water infiltration is important for improved crop productivity and environmental sustainability, but the combined effects of cover crops (CCs) and tillage on cumulative infiltration and infiltration parameters are not fully understood. The objectives of this study were to evaluate the influence of CCs and tillage on cumulative water infiltration and infiltration parameters. The field was set up using a randomized complete block design with two levels of CCs (CCs vs no cover crop [NC]) and two levels of tillage (till vs no-till [NT]). The CCs used included winter wheat (Triticum aestivum) and crimson clover (Trifolium incarnatum), and the tillage included disc tillage (to a depth of 10 cm). Results showed that CCs and tillage significantly increased the Parlange and Green-Ampt model estimated sorptivity and saturated hydraulic conductivity parameters during 2022 compared with NC and NT, respectively. Additionally, K Guelph was significantly higher under CC compared with NC during both years, suggesting that CCs can increase groundwater recharge. While CC-Till management had the highest 2-h cumulative infiltration, tillage only significantly increased water infiltration during early times, and CCs increased water infiltration during the infiltration period. Conclusively, CCs can improve the ability of tillage to increase water infiltration.

Integrating Farmers’ Perspectives into Earth System Model Development: Interviews with End Users in the Willamette Valley, Oregon, to Guide Actionable Science

Abstract This paper analyzes findings from semistructured interviews and focus groups with 31 farmers in the Willamette Valley in which farmers were asked about their needs for climate data and about the usability of a range of outputs from the Community Earth System Model, version 2 (CESM2), for their soil management practices. Findings indicate that climate and soils data generated from CESM and other Earth system models (ESMs), despite their coarse spatial scale resolutions, can inform farmers’ long-term decisions, but that the data would be more usable if the outputs were provided in a format that allowed farmers to choose the variables and thresholds relevant to their particular needs and if ESMs incorporated farmer practices including residue removal, cover cropping, and tillage levels into the model operations so that farmers could better understand the impacts of their decisions. Findings also suggest that although there is a significant gap in the spatial resolution at which these global ESMs generate data and the spatial resolution needed by farmers to make most decisions, farmers are adept at making scalar adjustments to apply coarse-resolution data to the specifics of their own farm’s microclimate. Thus, our findings suggest that, to support agricultural decision-making, development priorities for ESMs should include developing better representations of agricultural management practices within the models and creating interactive data dashboards or platforms.

Effect of Tillage Practices and Fertility Levels on Growth, Yield Attributes and Yield of Wheat in Rice- Wheat Cropping System

This study was conducted at Agronomy Research Farm, CSAUAT, during rabi 2021-22 and 2022-23. The experiment was laid out into Split plot design with3 replication. Two levels of tillage viz. (1) Conventional tillage Two ploughing followed by sowing), (2) Reduce tillage (one ploughing followed by sowing were randomly allotted to main plot while ten 10 fertility levels. Basis on the pooled data the results of the study revealed that in case of tillage practices among the growth parameters; maximum plant height at 30, 60, 90 DAT and at harvest is 26.25, 46.26, 87.43, and 92.38 cm respectively, number of leaves plant-1 at 30, 60, 90 DAT and at harvest is 5.47, 16.51, 19.34 and 20.18 respectively, leaf area index at 30, 60, 90 DAT and at harvest is 0.553, 3.13, 4.48 and 5.05 respectively, relative growth rate at 30, 60, 90 DAT is 24.33, 14.48 and 3.82 g day-1 respectively, among the yield attributing characters maximum ear length (11.07 cm) , number of grain ear-1 (41.08), grain weight ear-1 (1.54 g) and 1000 grain weight (36.93 g) and among the productivity parameters; maximum grain yield (51.31 q ha-1), straw yield (67.21 q ha-1), biological yield (118.52 q ha-1) and harvest index (43.22 %) were recorded under the conventional tillage. Similarly in case of fertility levels growth parameters, yield attributing characters and productivity parameters were associated with 125 % RDF + chloromequate chloride.

Management of soil cover and tillage regimes in upland rice-sweet corn systems for better system performance, energy use and carbon footprints

This study investigates the effects of tillage and mulching regimes on rice-sweet corn systems in the lower Gangetic plains, focusing on region-specific and crop-specific impacts on soil-crop-environmental parameters. The experiment consisted of three levels of tillage: conventional (CT), minimum (MT), and zero (ZT), and four levels of mulching: live, leaf litter, paddy straw, and no mulching. The results show that ZT tillage resulted in higher bulk density (BD) compared to other treatments, despite an increase in soil organic carbon (SOC). Live and leaf litter mulching led to slight reductions in BD in the upper soil layers. CT resulted in net depletion of SOC whereas ZT registered a positive sequestration rate of 1.19 Mg ha−1 yr−1. Live and leaf litter mulching increased SOC sequestration by 42.6% and 38.8% compared to paddy straw mulching, respectively. Initially, ZT resulted in a 10.3% reduction in system productivity compared to CT, while MT yields were comparable to CT. However, mulching regimes consistently improved production by 16.4%–25.2% as compared to no mulch. ZT and MT were found to be more affordable than CT, with cost savings of 18.2% and 6.8%, respectively. ZT had the highest B: C ratio, indicating better economic efficiency. Among the mulching treatments, live mulching was the most economical. Both ZT and MT saved input energy by approximately 22.9% and 13.5%, respectively compared to CT. Live mulching resulted in the highest net energy and energy output. Compared to CT, ZT reduced carbon footprint (CF) by 41.5 and 22.2% in rice and sweet corn, respectively. MT scored midway between ZT and CT in all parameters. CT exhibited several limitations, including high input energy requirements, high cost of cultivation, poor economic efficiency, negative environmental impacts, and loss of SOC. ZT initially experienced yield reduction and lower net returns in the early years. Therefore, MT was identified as the best alternative in the initial years before transitioning completely to ZT, as it provided comparable yields to CT with better overall benefits. Among the soil cover regimes, live mulching was found to be the most favorable option across all dimensions.

Assessing soil health in a thermic region of the southern great plains, using the soil management assessment framework (SMAF)

The soil management assessment framework (SMAF) has been widely used as a tool to quantify soil health. However, SMAF was developed using data from only a few climate conditions in the United States and regional verification is often suggested. We evaluated SMAF's short-term performance in a thermic/hyperthermic region, aiming to 1) evaluate the sensitivity of SMAF scores to changes in individual soil properties and 2) quantify soil health changes using SMAF. Treatments include two levels of summer crop and two levels of tillage in an annually planted wheat system. SMAF soil health metrics were measured for Burleson clay soil (BC site) and Parrita sandy clay loam soil (PSCL site) for 0–5 cm soil depth. At the BC site, βgluc and SOC SMAF scores displayed no statistical differences when compared to their respective soil properties. βgluc measurement also helped to highlight the treatment difference observed for wheat yield. This suggests that scoring curves of βgluc used in SMAF may need to be modified, especially for clayey soils. The results also show that SMAF scores were not correlated with wheat yield at both sites, suggesting that multiple year data may be needed to understand this relationship. Overall, in a thermic region, SMAF was found to be helpful to understand short-term soil health status. However, due to clay correction in SMAF algorithm, SMAF scores can show lower sensitivity in the clayey soils of these thermic regions.

Low rates of sugarcane bagasse‐derived biochar have limited effects on soil properties and sugarcane crop yield

AbstractSugarcane (Saccharumspp.) represents the most valuable row crop in Louisiana. High levels of biomass production and extensive tillage have degraded portions of the state's alluvial soils used to grow sugarcane. In addition to sucrose, processing the crop generates excess bagasse each year, which can represent a disposal problem for sugar factories. However, converting the bagasse to biochar at nearby pyrolysis facilities may prove to be an economical means of improving degraded soils. The objective was to determine the impacts of low rates of biochar (<3.2 mt ha−1) on soil physical, chemical, and biological properties. Plant available nutrient levels were marginally impacted by biochar additions as the biochar exhibited a relatively low surface area and neutral pH. Bagasse‐derived biochar did not affect soil nitrate retention or leaching, and overall recovery was >86%. Biochar did not increase soil CO2evolution, indicating its stability as a soil carbon amendment. However, adding biochar with mineral nitrogen decreased CO2evolution, compared to biochar alone, indicating a negative priming effect. Soil moisture retention was minimally impacted by biochar. Cane yield, sucrose content, and sucrose yield were not statistically affected by applying biochar with or without starter fertilizer at planting. Overall, the results indicate that lower levels of bagasse‐derived biochar minimally impacted soil properties and crop yield; however, the biochar was stable in soil and may find utility as a carbon‐rich amendment should carbon credits prove to be an additional source of grower or land‐owner revenue.

Ground beetles suppress slugs in corn and soybean under conservation agriculture.

Conservation agriculture practices such as eliminating tillage and planting high residue cover crops are becoming increasingly important in field crop systems in the US Mid-Atlantic. However, these practices have sometimes been associated with an increase in moderate to severe damage to field crops by slugs. Conserving natural enemy populations is a desirable way to manage slug infestations because remedial control measures are limited. Here, we tested the effects of conservation practices, weather, and natural enemies on slug activity-density measured by tile traps placed among 41 corn and soybean fields during the spring of 2018 and 2019 in the Northern Shenandoah Valley, Virginia, USA. We found that a positive effect of cover crops on slug activity-density was reduced by tillage and that slug activity-density declined with increasing ground beetle activity-density. Slug activity-density also declined with decreasing rainfall and increasing average temperature. Weather was the only significant predictor of ground beetle activity-density, which was reduced in sites and weeks that were relatively hot and dry or that were cool and wet. However, we also found a marginally significant negative effect of pre-plant insecticides on ground beetles. We suggest that the observed interacting effects of cover crops and tillage reflect favorable conditions for slugs provided by increased small grain crop residue that can be mitigated to some extent by even low levels of tillage. More broadly, our study suggests that implementation of practices known to promote recruitment of ground beetles in crop fields can improve natural suppression of slugs in corn and soybean that are being increasingly cultivated according to conservation agriculture practices.

Response of rainfed Indian mustard to different tillage practices and mulching

A field experiment was conducted during the rabi season of 2019 at College of Agriculture, Central Agricultural University, Imphal, Manipur. The experiment included the combination of two soil tillage systems viz., Conventional Tillage (L1) and Minimum Tillage (L2) and four different mulching materials viz., No mulch (M1); Rice straw mulch (M2); Polythene mulch (M3) and Tree leave mulch (M4). The Experiment was laid out in a split-plot design with different levels of tillage (main plot), and mulching materials (subplot) and each treatment were replicated thrice. The growth and yield of Indian mustard were influenced by different tillage practices and mulching. Maximum plant height (165.33 cm.), number of siliquae per plant (197) and seed yield (1790 kg/ha ) and oil yield (692 kg/ha) were recorded in a combination of (L1M3) which received in Conventional tillage + Polythene mulch and minimum seed yield was recorded in a combination of (L2M1) 1441 kg/ha which received in Minimum tillage + No mulch. Maximum harvest index was recorded in a combination of (L1M2) 27.50% which was received in Conventional tillage +Rice straw mulch and minimum harvest index was recorded in a combination of (L1M4) 24.13% which was received in Conventional tillage + Tree leaves to mulch. The highest benefit-cost ratio (0.72) was recorded in Minimum tillage + Rice straw mulch because there was less input cost for tillage or ploughing activities and mulching material cost. The highest energy use efficiency, and energy productivity but lowest specific energy was observed in Minimum tillage with No mulch and energy use efficiency, and energy productivity but highest specific energy was observed in Minimum tillage with Rice straw mulch.

Effects of Carbon Amendments, Tillage and Cover Cropping on Arbuscular Mycorrhizal Fungi Association and Root Architecture in Corn and Cotton Crop Sequence

A field experiment was conducted to study the effects of carbon amendments, tillage, and cover cropping on arbuscular mycorrhizal fungi (AMF) association and root architecture at Farm Services at Texas A&M University. Three levels of carbon amendments at the rate of 500 kg C ha−1 (biochar, composted biosolid, and control (no carbon amendment)), two levels of tillage (conventional disking (CT) and no tillage (NT)), and two levels of cover crop (a mixture of oat, mustard, and pea (CC) and no cover crop (NCC)) were arranged in a split-split plot design with four replications. Over a two-year crop sequence of corn followed by cotton, AMF colonization of roots was 4.43% greater in biochar-treated soil than in the control treatment. Colonization in cotton was 5.17% and 6.09% greater under NT and CC treatments, respectively, compared to CT and NCC. Carbon amendments did not alter corn root length but did alter root angle at 20–30 cm. Carbon amendments did not affect root angle under CC. However, tillage did affect CC root length and angle. Root length and root angle were found to differ among the cover crop species. The results imply that farmers may combine certain practices to optimize and harness the benefits of AMF.

Field measurement of wind erosion flux and soil erodibility factors as affected by tillage and seasonal drought

AbstractDuring periods of no or low crop growth in dryland cropping systems, tillage can reduce residue coverage and thereby elevate wind erosion risk. We measured wind erosion on a silt loam, Haplustoll soil in North Dakota (456 mm precipitation yr–1) in response to levels of tillage applied once in spring during fallow following a small grain–sunflower (Helianthus annuus L.) rotation. Treatments were no‐tillage (NT), one‐pass tandem disk tillage (TDT), and two‐pass offset disk tillage (ODT). Erosion flux was measured with sediment samplers near peripheries of >1‐ha replicated plots from May through September 2003 and 2004. Soil losses in ODT, TDT, and NT were 12.0, 4.8, and 2.1 Mg ha–1, respectively, in 2003 and 2.6, 1.6, and 1.4 Mg ha–1 in 2004. The greatest loss, 12.0 Mg ha–1, was equivalent to 1‐mm soil depth. The two‐ to fivefold greater erosion in 2003, a year with 2 mo of <30% of average precipitation, appears linked to a decline in residue coverage. Coverage remained about the same in NT and increased in tilled treatments during 2004 with more average precipitation. Our measurements of wind erosion have shown how the residue‐destroying effects of a single tillage event can be considerably exacerbated by a moderate, seasonal drought. This indicates the critical importance of NT for limiting soil and residue disturbance and reducing wind erosion risk from drought‐affected plant growth failure in semiarid cropping systems.

Severe drought rather than cropping system determines litter decomposition in arable systems

Litter decomposition is a fundamental process in soil carbon dynamics and nutrient turnover. However, litter decomposition in arable systems remains poorly explored, and it is unclear whether different management practices, such as organic farming, conservation agriculture can mitigate drought effects on litter decomposition.Thus, we examined the effects of a severe experimental drought on litter decomposition in four cropping systems, i.e., organic vs. conventional farming, each with two levels of tillage (intensive vs. conservation tillage) in Switzerland. We incubated two types of standard litter (tea bags), i.e., high-quality green tea with a low C:N ratio and low-quality rooibos tea with a high C:N ratio. We assessed litter decomposition during the simulated drought and in the post-drought period during three years in three different crops, i.e., pea-barley, maize, and winter wheat. Subsequently, we assessed whether decomposition in the four cropping systems differed in its resistance and resilience to drought.Drought had a major impact on litter decomposition and suppressed decomposition to a similar extent in all cropping systems. Both drought resistance and resilience of decomposition were largely independent of cropping systems. Drought more strongly reduced decomposition of the high-quality litter compared to the low-quality litter during drought conditions regarding the absolute change in mass remaining (12.3% vs. 6.5 %, respectively). However, the decomposition of high-quality litter showed a higher resilience, i.e., high-quality approached undisturbed decomposition levels faster than low-quality litter after drought. Soil nitrate availability was also strongly reduced by drought (by 32–86 %), indicating the strong reduction in nutrient availability and, most likely, microbial activity due to water shortage. In summary, our study suggests that severe drought has a much stronger impact on decomposition than cropping system indicating that it might not be possible to maintain decomposition under drought by the cropping system approaches we studied. Nevertheless, management options that improve litter quality, such as the use of legume crops with high N concentrations, may help to enhance the resilience of litter decomposition in drought-stressed crop fields.

Enhancement of Wheat Productivity Under Different Levels of Tillage, Seeding Rate and Nitrogen Sources in An Arid Region

Enhancement of Wheat Productivity Under Different Levels of Tillage, Seeding Rate and Nitrogen Sources in An Arid Region

Effect of tillage and irrigation management on radiation use efficiency of wheat (Triticum aestivum)

Field experiments were conducted during 2015–16 and 2016–17 on wheat (cv HD2967) in a sandy loam soil at ICAR-Indian Agricultural Research Institute, New Delhi to study the effect of tillage and irrigation management on radiation use efficiency (RUE) of wheat. The treatments comprising of three levels of tillage as main plot factor (Conventional tillage, Deep tillage and No tillage) and three levels of irrigation as subplot factor (I1: 1 irrigation, I3: 3 Irrigations and I5: 5 Irrigations) were evaluated in a split plot design. The results showed that there was no significant difference among tillage treatments with respect to extinction coefficient. However, pooled data of 2 years, extinction coefficient due to I5 was significantly higher than that of I3 and I1 by 8.8 and 23.8%, respectively, and extinction coefficient due to I3 was significantly higher than I1 by 13.8%. There was no significant difference among the tillage treatments with respect to radiation use efficiency (RUE) of wheat, but RUE increased significantly with increasing irrigation level. RUE of wheat under I5 was significantly higher than that of I1 and I3 treatments but there was no significance difference between I1 and I3 with respect to RUE of wheat in both the years.

Mechanism of Intermittent Deep Tillage and Different Depths Improving Crop Growth From the Perspective of Rhizosphere Soil Nutrients, Root System Architectures, Bacterial Communities, and Functional Profiles.

Long-term conventional shallow tillage reduced soil quality and limited the agriculture development. Intermittent deep tillage could effectively promote agricultural production, through optimizing soil structure, underground ecology system, and soil fertility. However, the microecological mechanism of intermittent deep tillage promoting agriculture production has never been reported, and the effect of tillage depth on crop growth has not been explored in detail. In this study, three levels of intermittent deep tillage (30, 40, and 50 cm) treatments were conducted in an experimental field site with over 10 years of conventional shallow tillage (20 cm). Our results indicated that intermittent deep tillage practices helped to improve plant physiological growth status, chlorophyll a, and resistance to diseases, and the crop yield and value of output were increased with the deeper tillage practices. Crop yield (18.59%) and value of output (37.03%) were highest in IDT-50. There were three mechanisms of intermittent deep tillage practices that improved crop growth: (1) Intermittent deep tillage practices increased soil nutrients and root system architecture traits, which improved the fertility and nutrient uptake of crop through root system. (2) Changing rhizosphere environments, especially for root length, root tips, pH, and available potassium contributed to dissimilarity of bacterial communities and enriched plant growth-promoting species. (3) Functions associated with stress tolerance, including signal transduction and biosynthesis of other secondary metabolites were increased significantly in intermittent deep tillage treatments. Moreover, IDT-30 only increased soil characters and root system architecture traits compared with CK, but deeper tillage could also change rhizosphere bacterial communities and functional profiles. Plant height and stem girth in IDT-40 and IDT-50 were higher compared with IDT-30, and infection rates of black shank and black root rot in IDT-50 were even lower in IDT-40. The study provided a comprehensive explanation into the effects of intermittent deep tillage in plant production and suggested an optimal depth.

Evaluation of Seasonal Effects of Tillage and Drainage Management Practices on Soil Physical Properties and Infiltration Characteristics in a Silt-Loam Soil

The impacts of tillage and drainage managements on soil infiltration characteristics need to be scrutinized for a better understanding and prediction of soil hydrological processes, such as runoff, evapotranspration and soil water storage. The objectives of this study were i) to evaluate the effects of tillage and drainage practices on soil physical properties and water infiltration, and ii) to compare prediction accuracy of estimated and optimized infiltration model characteristics for the observed and predicted quantities of infiltration process in the soil. The research site contains the Crosby-Kokomo soil series (fine, mixed, mesic, Aeric Ochraqualf and fine, mixed, mesic Typic Argiaquoll, respectively). The experiment was a two factorial completely randomized block design with two levels of tillage (chisel plow (CH) and no-till (NT)) and two levels of drainage (drained (D) and undrained (UD)) with three replicates. Soil bulk density (ρb), saturated hydraulic conductivity (Ksat), soil moisture retention curves (SMRC), soil infiltration capacity and piezometric water head in each treatment were also measured. Soil drainage flows at each drain lateral and outlet discharges were measured. The results showed that The UD treatments were always higher for Ksat values than the D treatments regardless of the tillage practices for both depths and the CH treatments always had greater Ksat values than those in the NT at both the depths regardless of drainage practices. The D treatments reduced the soil bulk density by 4.2 and 0.8 % in the surface soil and 4.61 and 6.7% for the subsurface soil in respect to no-till-UD and chisel-UD treatments. The UD treatments had higher bulk density at both of the depths than those of the D treatments regardless of tillage practices except the CH-UD treatments. The NT had higher bulk density at both depths of the soil than those of the CH treatments regardless of drainage practices. Drainage increased pore size distribution significantly higher than the UD treatments (p<0.05). The D treatments had significantly higher storage pores and effective pores (9.37%) (pores retaining water at -10kPa pressure head) than the ones in the UD treatments (8.96%) (p<0.05). The NT treatments yielded higher infiltration rates than the CH and the D treatments produced higher apparent infiltration rates and cumulative infiltration values than the UDs. The changes in soil physical properties were found to be strongly and significantly dependent on season, soil depth, and rainfall (p<0.05). The optimized infiltration models predicted larger range of infiltration rate values for each treatment than the estimated infiltration models, indicating that the optimization produced higher accuracy and validity of the predicted models in the field. To conclude, soil dry bulk density, soil saturated hydraulic conductivity, and increased macropore volumes can significantly impact soil hydrological responses to soil water infiltration, soil water storage and drainage flow under conservation tillage and drainage management practices on a seasonal basis. This impact enhances greater potential to capture water in soil for future crop use in the study site.

Growth and production of sweet corn (Zea mays saccarata sturt L) with soil treatment and number of seeds per planting hole

Sweet corn production in Indonesia from is volatile and unstable. Unoptimal production of sweet corn in North Sumatra is caused by land conditions, plant populations, pest and disease and level of soil fertility. Effective and efficient soil tillage, crop spacing and number of seeds will affect the physical properties of the soil and plant productivity. This study aims to observe the best planting and tillage methods for maize. This study used a split plot design which is repeated three times with two factors, i.e. 3 levels of number of seeds per planting hole and 3 levels of soil tillage. The results showed that the treatment of tillage and the number of seeds per planting hole give significant effect on the variables of plant height, stem diameter, and total production. The interaction of these two factors showed an influence on the parameters of sweet corn plant height. The treatment of 2 seed per planting hole and 1 time of soil tillage show the best productivity compared to other treatments.

Response of canola yields from marginal lands managed with tillage practices

Abstract In recent years the discourse regarding the effective use of dwindling agricultural spaces for food, fiber, or fuel production has grown and it is becoming increasingly important to manage non-agricultural or marginal spaces that make them suitable for crop production. Highly eroded, highly compacted, low nutrient soils, similar to those found along highway rights-of-way (ROWs) offer unique field characteristics that can be used to study crop production potentials and land use decisions. This work evaluated the feasibility of maintaining a canola crop production system on the non-agricultural soils of highway ROWs across the humid subtropical climate within North Carolina, USA as a bioenergy feedstock for renewable fuels. Specific objectives included examination of (1) three different North Carolina geoclimatic conditions and (2) three levels of tillage (conventional (CT), minimum (MT), and no-till (NT)) on canola (Brassica napus L.) grain yields cultivated on ROW soils. Field experiments were conducted for two growing seasons in the Inner Coastal Plain, Piedmont, and Mountains regions and assessed main and interaction effects among tillage, site, and year of cultivation on crop productivity. After season 1, CT produced the highest average yield (1.24 Mg ha−1) followed by MT (0.93 Mg ha−1) and NT (0.86 Mg ha−1), respectively. In the second year, the comparative intensity of productive effects from CT was lower, and plots cultivated under MT resulted in the highest average yields (2.70 Mg ha−1), followed by CT (2.69 Mg ha−1) and NT (1.96 Mg ha−1), respectively. Yields observed were comparable to regional canola grain yields, and no significant difference was observed between yields under CT versus MT. These findings suggest that reduced levels of tillage on ROW soils in North Carolina hold the potential to produce yields comparable to those realized in traditional agricultural soils, and targeted tillage practices can support improved suitability of marginal crop production spaces.

Integrated Effect of Tillage and Herbicides on Wheat Crop

Combining tillage with herbicides is an economical and efficient method for weed management and yield improvement in wheat. A two-year study was conducted having three tillage levels viz. 2″ tillage (shallow tillage, ST), 4″ tillage (conventional tillage, CT) and 6″ tillage (deep tillage, DT). The weed control treatments were five including three herbicides i.e. bromoxynil + MCPA (a broad-leaf weed killer), fenoxaprop-p-ethyl (a grass killer) and isoproturon + carfentrazone (a broad-spectrum herbicide), along with a hand weeding (HW) and a weedy check (WC). Results showed that the recorded parameters were significantly affected by the varying tillage depths, herbicide applications and their interactions. The weed density and biomass were the highest in ST and the lowest in DT, while among the weed control treatments, the weed density and biomass were highest in WC and lowest in HW. On the other hand, the DT treatments resulted in highest number of spikes m−2, 1000-grain weight (TGW), biological yield and grain yield; while ST showed the lowest values. Among the weed control treatments, the number of spikes, TGW, biological and grain yields were the highest in HW and the lowest in WC treatments. The herbicide isoproturon + carfentrazone performed the best among the three applied herbicides in diminishing the weed population density and biomass, and improving the number of spikes, TGW, biological and grain yields. In conclusion, the combination of deep tillage and herbicide isoproturon + carfentrazone can prove to be the best option for optimum weed management in wheat at higher altitudes.

Soil microstructure as affected by tillage, rotation and residue management in a sweet sorghum-based cropping system in soils with low organic carbon content in South Africa

Soil aggregation is regarded as a key indicator of soil quality and behaviour that is mainly influenced by land use and management. There is lack of information on the effects of conservation agriculture (CA) on soil aggregation in low soil organic carbon (SOC) soils of South Africa. This study therefore aimed to quantify the effect of tillage, crop rotation and crop residue management on aggregate stability, binding agents and the resulting aggregate microstructure in a sweet sorghum-based cropping system in a low organic carbon soil. Two tillage levels; no-till (NT) and conventional tillage (CT), two crop rotations, i.e., sweet sorghum-grazing vetch-sweet sorghum (S-V-S) and sweet sorghum-fallow-sweet sorghum (S-F-S) and three crop residue retention levels, i.e., 0%, 15 % and 30 % were tested. The aggregate microstructure was quantified on aggregates of ∼5 mm diameter with micro-focus X-ray computed tomography (μXCT) and image analysis was done using VGstudio MAX 3.2. Aggregate stability, soil organic carbon and glomalin related soil protein content (GRSP) were statistically higher under NT than in CT. GRSP was also enhanced by 30 % residue retention compared to other residue management practices. NT and CT accompanied by 30 % residue retention had the highest total porosity. NT + S-V-S + 30 % treatment combination generally had higher observed total porosity, higher frequency of pores within each pore class and denser microstructure visualisation. This study showed that tillage is the main factor that influences soil aggregation followed by residue management. Thus, application of NT + S-V-S+ 30 % enhanced soil quality in low SOC soils after three years. The study also demonstrated that aggregate stability is linked to aggregate microstructure and regular pores are dominated in degraded soils with low SOC.

Sowing uniformity of bed-type pneumatic maize planter at various seedbed preparation levels and machine travel speeds

Precision planters are important machines in the regime of modern technological agriculture. Field conditions, seed metering system and machine operating parameters affect the pneumatic planter performance. The pneumatic planter was evaluated to determine the effect of three tillage levels (L1, L2, and L3) and four travel speeds (S1, S2*, S3 and S4). The sowing uniformity of the planter was observed with respect to the horizontal distribution of seeds within a row and described by using the precision index (Ip), the multiple index (Imult), the miss-seeding index (Imiss) and the quality of feed index (Iqf). The results revealed that the tillage levels (L) and travel speed (S) had a significant effect (p<0.05) on dependent variables. The maximum Imiss (22.12%) was observed at L1 and S4 whereas the maximum Imult was observed at L1 and S1. The mean values of missing-, multi-, quality- feed and precision indices were 5.14%, 5.833%, 89.03% and 17.85% at L3, respectively. The mean values of multi-index 17.59%, 14.44%, 12.40% and 10.18%, quality feed index 74.07%, 75.92%, 75.74% and 74.07% and precision indices 21.47%, 23.26%, 25.51% and 28.53% were at S1, S2, S3 and S4, respectively. The study showed that maize could be seeding within an acceptable precise range by bed-type pneumatic planter subjected to the proper seedbed preparation level. Keywords: sowing uniformity, pneumatic planter, tillage levels, travel speed DOI: 10.25165/j.ijabe.20211401.5054 Citation: Ahmad F, Adeel M, Qiu B J, Ma J, Shoaib M, Aamir S, et al. Sowing uniformity of bed-type pneumatic maize planter at various seedbed preparation levels and machine travel speeds. Int J Agric & Biol Eng, 2021; 14(1): 165–171.