Effects Of Different Tillage Practices Research Articles

Effects of different tillage practices and cropping systems on soil fertility and soil properties in maize

Effects of different tillage practices and cropping systems on soil fertility and soil properties in maize

Characterization of soil pores in strip-tilled and conventionally-tilled soil using X-ray computed tomography

Changes in soil pore size distribution and connectivity can affect contaminant transport. Climate, soil type, and agricultural management practices can influence these characteristics. Conservation tillage practices, such as strip tillage, have been promoted as agricultural management practices that can help reduce soil erosion and nutrient loss in runoff. However, limited information exists in the literature on the effect of strip tillage on soil pore characteristics. Thus, the objective of this research study was to assess the effects of different tillage practices i.e., conventional tillage (CT) vs. strip tillage (ST), on soil pore properties and quantify change in soil pore characteristics as a function of season. Undisturbed cylindrical soil columns (150 mm diameter and 640 mm length) were collected from a field in Alabama, USA planted with cotton (Gossypium hirsutum L.) under ST and CT treatments during two seasons i.e., fall 2021 and spring 2022. Soil cores were collected from CT and ST portions of the field, in the fall, following cotton harvest and before planting a cover crop (season 1), and in the spring, after the cover crop had matured (season 2). X-ray computed tomography was used to scan the soil cores and quantify soil pore characteristics. Results show that the ST treatment had significantly (p < 0.05) greater macroporosity values, network density, macropore length density, and interconnectivity compared to the CT in season 1. This was attributed to ST being a minimally disturbed treatment: thereby, it has a better chance of preserving cracks and biological activity as compared to CT, which is more prone to destruction of large macropores. The pore properties also showed a drastic decrease in values during season 2, especially for the top 200 mm of the soil profile in response to rainfall induced soil reconsolidation in both the tillage systems. Overall, this study showed that pore morphology can be affected by tillage and seasonal aspects associated with them.

Effect of Different Tillage Practices on the Growth and Yield of Sweet Potatoes (Ipomoeo Batata L) in Asaba, Delta State Nigeria.

The research was carried out to determine the effect of different tillage practices on the growth and yield of sweet potatoes (Ipomoeo batata L) in Asaba, Delta State Nigeria. Field experiment was carried out at the teaching and research farm of Federal College of Education (Technical),Asaba, Delta State Nigeria. The experiment was laid out in a randomized complete block design (RCBD) made up of four treatments: To – control (ridge tillage), T1 – Zero tillage, T2 – Mound tillage, T3 – Flat tillage and was replicated three times (4 x 3). Land area of 100m x 100m was cleared and divided into three to represent, replicates 1, 2 and 3. Random samples of five plants were tagged for data collection at four, six and eight weeks’ intervals after germination of plants to measure the growth parameters, while yield was measured in kg using weighing scale. Data analysis was carried out using the statistical package of social science (SPSS) with general linear model procedure analysis of variance (ANOVA) to determine the treatment effect and Duncan Multiple Range Test was used for mean separation difference in mean were considered significant at an alpha level of 95% or higher (p ≤ 0.05). Findings from the study revealed that tillage practices had significant effect (p&lt;0.05) on the growth and yield of sweet potatoes. The study recommended the adoption of ridge tillage practices for increased growth and yield of sweet potatoes.

Tillage and Crop Residue Effects on Soil Carbon and Moisture for Wheat (Triticum aestivum L.) Productivity in Semiarid Regions of Tigray, Ethiopia

Soil tillage is one of the basic agriculture operations. However, the appropriate tillage type, tillage time, and tillage frequency for effective moisture harvesting and sustainable soil fertility were not investigated for Tigray. A field experiment was conducted during 2016 to 2018 in Enderta district. It was done with the objective of evaluating the effect of different tillage practices on wheat productivity. The treatments were (I) permanent bed+ crop residue,(II) three times tillage with furrow, (III) two times tillage with furrow, and (IV) farmer’s practice tillage. A randomized complete block design with three replications was set up. Measurement of soil moisture content was conducted using the gravimetric method. Agronomic parameters were collected and analyzed using GenStat. Marginal rate of return was also estimated from the total revenue and total variable cost. Positive effect was found on soil fertility, soil moisture content, and grain yield due to the tillage practice and crop residue. Permanent bed+ crop residues and three tillage furrow increased soil moisture content, organic carbon, and total nitrogen, as well as the yield and yield components at the second and third year of experimentation. The highest grain yield 2952 kg ha-1 and biomass yield 8582 kg ha-1 were recorded at the three tillage furrow in the third year of experimentation. The 59,056 ETB was the highest net revenue recorded at three times tillage with furrows. From this result, it can be concluded that without adding any additional input instead of changing agricultural operation techniques, the economic benefit of farmers’ could be improved by 48%. Therefore, three tillage practices with furrow is the most economically feasible technology for farmers to increase wheat productivity in the semiarid area of Enderta district.

Effects of long-term tillage practices on the stability of soil aggregates and organic carbon in black soil farmland.

We examined the effects of different tillage practices on plough layer soil structure and organic carbon stabilization in black soil farmland with a long-term positioning platform. The wet-sieving method and infrared spectroscopy method were used to investigate the impacts of conventional tillage (CT), no-tillage (NT), sub-soiling tillage (ST), and moldboard plowing tillage (MP) on soil aggregates distribution and organic carbon characteristics in 0-40 cm soil layers. Compared to CT, both NT and ST treatments significantly increased the proportion of large macroaggregates (>2 mm) in the topsoil layer (0-20 cm)and that of small macroaggregates (0.25-2 mm) in the subsoil layer (20-40 cm) for NT, ST, and MP. NT, ST, and MP treatments resulted in higher mean weight dia-meter (MWD) and mean geometric diameter (GMD) of soil aggregates in both the topsoil and subsoil layers. NT treatment improved organic carbon contents in bulk soil and large macroaggregates in the topsoil layer, while ST and MP enhanced organic carbon contents in bulk soil and large macroaggregates in the subsoil layer. The contribution rate of small macroaggregates organic carbon content to the total was between 68.9% and 83.4%. Furthermore, the organic carbon chemical stabilization of soil body and aggregates increased in the topsoil and subsoil layers under NT treatment compared to others. The MWD had a positive correlation with the organic carbon content and chemical stability of soil body and small macroaggregates. These findings offered a theoretical basis for understanding the impacts of different tillage practices on the stability of soil aggregate and organic carbon in black soil region.

Effects of tillage practice on fungal and actinobacterial cellulolytic community with different humified particle‐size fractions in a double‐cropping paddy field

AbstractSoil cellulose plays a vital role in keeping or increasing carbon (C) cycling and fertility of rice fields. There is a close relation between soil fulvic acid (FA), humin (HM) fractions, and GH48, cbhI genes. However, the effects of different tillage practices on soil humus C content composition, GH48, and cbhI genes abundances in different soil particle‐size fractions of double‐cropping rice fields still need to be further investigated. Therefore, the impacts of different short‐term tillage practices on soil GH48 and cbhI genes abundances in double‐cropping rice fields were conducted. This experiment set up different tillage practices: rotary tillage with crop straw removed as a control (RTO), conventional tillage with crop straw in put (CT), rotary tillage with crop straw in put (RT), and no‐tillage with crop straw retain (NT). The result indicated that the distribution of soil humus, and GH48, cbhI genes abundances were significantly enhanced under combined applied with tillage and crop straw incorporation conditions. Soil FA, HM, and humic acid (HA) C content in 2000–50 μm and &gt;2000 μm fractions with RTO treatment were significantly lower than that of CT, RT, and NT treatments. This result showed that oalkyl and alkyl of HA and FA in 2000–200, 200–50, 50–2, and 2–0.1 μm fractions with CT, RT, NT, and RTO treatments were lower than that of &gt;2000 μm fraction. There was lower ARO% and more AL% of FA and HA in these fractions under the same tillage condition. The result showed that GH48 and cbhI genes abundances in these fractions with CT, RT, and NT treatments were significantly higher than that of RTO treatment. There had significantly positively correlated with GH48, cbhI genes abundances, and soil HA, FA, HM C contents, o‐alkyl C, and AL% of FA. Therefore, it was positively practiced for increasing GH48 and cbhI genes abundances in the double‐cropping rice fields by applying with tillage and crop straw incorporation.

Effects of long-term no-tillage on the functional potential of microorganisms involved in the nitrogen, phosphorus and sulfur cycles of black soil.

Understanding the effects of different tillage practices on functional microbial abundance and composition in nitrogen (N), phosphorus (P) and sulfur (S) cycles are essential for the sustainable utilization of black soils. Based on an 8-year field experiment located in Changchun, Jilin Province, we analyzed the abundance and composition of N, P and S cycling microorganisms and their driving factors in different depths of black soil under no til-lage (NT) and conventional tillage (CT). Results showed that compared with CT, NT significantly increased soil water content (WC) and microbial biomass carbon (MBC) at soil depth of 0-20 cm. Compared with CT, NT significantly increased the abundances of functional and encoding genes related to N, P and S cycling, including the nosZ gene encoding N2O reductase, the ureC gene performing organic nitrogen ammoniation, the nifH gene encoding nitrogenase ferritin, the functional genes phnK and phoD driving organic phosphorus mineralization, the encoding pyrroloquinoline quinone synthase ppqC gene and the encoding exopolyphosphate esterase ppX gene, and the soxY and yedZ genes driving sulfur oxidation. The results of variation partitioning analysis and redundancy analysis showed that soil basic properties were the main factors affecting the microbial composition of N, P and S cycle functions (the total interpretation rate was 28.1%), and that MBC and WC were the most important drivers of the functional potential of soil microorganisms in N, P and S cycling. Overall, long-term no tillage could increase the abundance of functional genes of soil microorganisms by affecting soil environment. From the perspective of molecular biology, our results elucidated that no tillage could be used as an effective soil management measure to improve soil health and maintain green agricultural development.

Effects of Different Tillage Practices and Nitrogen Fertiliser Application Rates on Soil-Available Nitrogen

The dynamics of nitrogen availability in soil result from the net amount of organic and inorganic inputs undergoing decomposition, mineralization, and immobilization. This varies with soil type, climate, and cropping system management practices. Hence, the interaction of these factors in a specific environment is important for nitrogen management and availability in any cropping system. This study evaluated the concentration of nitrate (NO3−) and ammonium (NH4+) in a maize monocropping system in a long-term trial under different tillage practices, i.e., no-till (NT), conventional tillage (CT), and rotational tillage (RT), and with different nitrogen (Urea) fertiliser application rates (0, 100, and 200 kg/ha N). The experimental area was a split plot with randomized tillage strips as the main plots, with the nitrogen fertiliser application rates forming the subplots. The results found the highest concentration of NO3− (7.728 mg/kg) and NH4+ (0.762 mg/kg) under the NT (p &lt; 0.05) compared to the other treatments. CT recorded the lowest amount of NH4+ (0.648 mg/kg) (p &lt; 0.05) compared to RT (0.758 mg/kg), while the concentration of NO3− (6.755 mg/kg) under the CT was relatively higher than under the RT (4.720 mg/kg). The results also showed that the 0–10 cm depth had a significantly (p &lt; 0.05) higher concentration of NO3− (6.787 mg/kg) and NH4+ (0.851 mg/kg), followed at the 20–30 cm depth with 6.229 mg/kg NO3− and 0.832 mg/kg NH4+. Soil samples taken at 10–20 cm depth recorded the lowest NO3− (6.188 mg/kg) and NH4+ (0.485 mg/kg). The study also found the highest NO3− concentration (0.452 mg/kg) with 200 kg/ha N (p &lt; 0.05), while the highest concentration of NH4+ (0.954 mg/kg) was found with 0 kg/ha N. The lowest concentrations of both NO3− (6.333 mg/kg) and NH4+ (0.561 mg/kg) were found with 100 kg/ha N. the no-till also had a significantly (p &lt; 0.05) higher NO3− (8.518 mg/kg) concentration with 200 kg/ha N compared to the CT (6.005 mg/kg) and RT (4.833 mg/kg). On the other hand, more NH4+ (1.478 mg/kg) was found with 0 kg/ha N under the NT compared to the CT (0.717 mg/kg) and the RT (0.669 mg/kg). The concentration of NH4+ was relatively low with 200 kg/ha N in the NT (0.545 mg/kg) and CT (0.598 mg/kg) but higher in the RT (0.813 mg/kg). In conclusion, the NT favoured the availability of NO3− and NH4+ in the studied cropping system; however, the concentration of these was affected by fertiliser application rate and depth. This suggested that each tillage system should be compatible with the type and the rate of inorganic nitrogen fertiliser for better crop production.

Long-term tillage and irrigation effects on aggregation and soil organic carbon stabilization mechanisms

Sustainable soil management practices are required in agriculture to enhance carbon sequestration and restore soil functions. Here, the aim was to investigate the effect of different tillage practices combined with or without irrigation on (i) soil organic carbon (SOC) content, (ii) fungal biomass and their relationships with aggregate size classes in the soil surface layer; further, (iii) the concept of soil particle saturation with SOC was tested to evaluate if a threshold was reached in a 14 year-experiment. Our hypothesis was that long-term irrigation, intensive tillage and their combination, would negatively affect soil aggregation and SOC stabilization. The experiment has started in 2003 on a research farm in Canterbury, New Zealand. The present work focused on two contrasting tillage practices –intensive tillage with 20–25 cm ploughing (IT) and direct drill (DD)– combined with sprinkler-irrigated and non-irrigated (hereafter called Rainfed) conditions in a split-plot experimental design. Soil samples (0–5 cm layer) were analyzed for pore size distribution, specific surface area and microbial biomass. Further, wet sieving was used to isolate large macroaggregates (LM, > 2000 μm), small macroaggregates (SM, 250–2000 μm), microaggregates (m, 53–250 μm), particle sized silt + clay fractions (s+c, < 53 μm) and Fine20 particles (<20 μm), followed by the analysis of aggregate morphology and SOC quantification in them. Results showed that both DD and Rainfed management increased total SOC content of the bulk soil. Only the LM fraction and the SOC therein (OC-LM) increased significantly in DD compared to IT, while m and s+c fractions and OC-m and OC-s+c did not differ between treatments. Macroaggregate breakdown processes and measured SOC therein had likely not reached steady-state conditions, as suggested by the lack of any SOC differences in the aggregate size classes < 250 µm. In contrast, the Fines20:SOC ratio differentiated between soils that had reached (i.e., DD) or not reached (i.e., IT) the saturation threshold. Finally, it was observed that a higher fungal:bacteria (F:B) ratio was generally accompanied by a greater LM fraction and mean weight aggregate diameter, highlighting the importance of fungi in the formation of LM. These results suggested that our hypothesis of detrimental effects on soil aggregation and SOC accumulation of both tillage and irrigation was not fully demonstrated yet. A longer study period would be required to better understand the effects of such practices of SOC storage.

Different responses of agroecosystem greenhouse gas emissions to tillage practices in a Chinese wheat–maize cropping system

To mitigate greenhouse gas (GHG) emissions of intensified agriculture, conservation practices are gradually being implemented in Chinese wheat–maize cropping systems. However, the effects of different tillage practices on agricultural field GHG emissions and subsequent global warming potential (GWP) are poorly documented. In this study, a three-year field experiment was conducted from 2019 to 2021 to assess the effects of tillage on the emissions of carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and eventually GWP. Compared to conventional tillage (CT), no-tillage (NT) significantly decreased CO2, CH4, and N2O emissions by 35.43%, 67.33%, 339.07%, respectively, which resulted in a decrease of 37.25% in GWP during three annual cycles. Based on the results of this study, soil could potentially act as a net source of CO2 and CH4 under both CT and NT, and a net sink of N2O under NT. Annually, non-growing season contributed 16.9%, 15.6%, and 13.8% soil CO2, CH4, and N2O fluxes, and 16.6% GWP under CT and 17.3%, 16.4%, 21.6%, and 17.3% under NT, respectively. Compared to CT, NT improved the aboveground biomass and grain yields of wheat by 21.3% and 13.3% from averaged results, respectively; no significant differences were found for maize yields. Although principal component analysis showed that soil temperature had higher correlations with CO2 emissions and GWP as compared to soil moisture, soil moisture affected GHG emissions more than soil temperature as demonstrated by the structural equation model. The modeling analysis found that NT increased soil moisture, pH, and bulk density, thus increasing soil organic carbon and decreasing total nitrogen content, eventually inhibiting GHG emissions. This research demonstrated that NT had the potential to mitigate GHG emissions, yet stability needed further investigation on long-term scales.∙Graphical

Effect of Different Tillage Practices on Sunflower (Helianthus annuus) Cultivation in a Crop Rotation System with Intercropping Triticosecale-Pisum sativum.

The objective of this work was to investigate the effect of different soil tillage practices on sunflower cultivation in a rotation system with intercropping of Triticosecale-Pisum sativum. For this purpose, a two-year experimental field with a 5% slope was established in central Greece. There were four treatments with three replications each. The treatments were as follows: (a) no tillage planting parallel to the contour (NTC-PAC), (b) conventional tillage planting parallel to the contour (CTC-PAC), (c) no tillage planting perpendicular to the contour (NTC-PEC), and (d) conventional tillage planting perpendicular to the contour (CTC-PEC). During the experiment, the plant height, leaf area index, specific leaf area, plants' total nitrogen, and plants' proteins were measured. According to the results, the plant height ranged from 64.9 (CTC-PAC) to 85.2 cm (NTC-PEC) for the first year and between 66.5-86.5 cm in for the CTC-PAC and NTC-PEC treatments in the second year. Furthermore, the leaf area index (LAI) and specific leaf area (SLA), plants' total nitrogen and protein content and N-uptake were affected positively by the no tillage practice. To conclude, sunflower is a promising crop in a rotation system intercropping Triticosecale-Pisum sativum, cultivated under rainfed sloping conditions.

Effects of minimum tillage and liming on maize (Zea mays L.) yield components and selected properties of acid soils in Assosa Zone, West Ethiopia

Soil acidity is a serious threat to crop production in Ethiopia. However, liming and soil management practices are effective for restoration of acid soils. The study was conducted to evaluate effects of different tillage practices, liming materials, and liming rates on maize (Zea mays L.) yield components as well as soil physicochemical properties in Assosa and Bambasi Districts of Assosa Zone. A split-split plot design of 2 tillage practices * 2 liming materials * 4 liming rates with three replications for one year was used on each location on farmer-managed plots. The study revealed that the tillage practices showed significant differences on grain per cob at both sites; BD (bulk density), available Cu and Zn at Amba-2 Kebele; whereas, thousand grain weights, CEC (cation exchange capacity), exchangeable Al 3+ , total acidity, exchangeable Mg 2+ , available Mn and Zn at Mender-49 Kebele. The liming materials used had shown significant difference on thousand grain weights, Av-P, exchangeable Mg 2+ , available Fe, Cu and Zn at Amba-2 Kebele; whereas, pH, exchangeable Al 3+ , total acidity, exchangeable Na + and Mg 2+ , available Cu and Zn at Mender-49 Kebele. Furthermore, different liming rates significantly affected all maize yield and yield component parameters as well as soil property parameters except BD and soil texture at both sites, OC (organic carbon) and exchangeable K + at Amba-2 Kebele were not significant. The interaction effects of the treatments showed significant differences on available micronutrients (Fe, Mn, Cu and Zn) at both Kebeles. Accordingly, the interaction of minimum tillage with recommended rate of dolomitic lime had improved maize productivity through ameliorating the physicochemical properties of acid soils in the study area. • Soil acidity drastically decline maize crop yield. • Minimum tillage has positive effect on soil acidity over the traditional tillage management. • Reclamation of acid soils with calcitic and dolomitic lime improves maize crop yield and yield components. • Minimum tillage and liming improve the physicochemical properties of acid soils.

Tillage Practices and Residue Management Manipulate Soil Bacterial and Fungal Communities and Networks in Maize Agroecosystems.

Tillage practices and residue management are highly important agricultural practices. However, very few studies have examined the influence of tillage practices and residue management on both bacterial and fungal communities and network patterns in consecutive years. We examined the effects of different tillage practices, including no tillage, rotary tillage, and deep tillage, on soil bacterial and fungal communities and co-occurrence networks following residue removal and residue retention in 2017 and 2018. This study showed that both bacterial and fungal communities were unaffected by tillage practices in 2017, but they were significantly impacted in 2018. Soil fungal operational taxonomic unit (OTU) richness was significantly enhanced by deep tillage compared with no tillage in 2018, while bacterial OTU richness was unaffected in either year. Tillage practices had differing effects on soil microbial co-occurrence networks, with rotary and deep tillage increasing the complexity of bacterial networks but simplifying fungal networks. However, residue retention only induced a shift in the fungal community and simplified soil bacterial and fungal networks in 2018. This study highlights the dissimilar responses of bacterial and fungal networks to tillage practices and emphasizes that tillage practice is more important than residue management in shaping soil microbial communities.

Studies on tillage and green manuring for enhancing productivity of wheat (Triticum aestivum)

A field experiment was conducted in 2016–17 and 2017–18 during kharif and rabi season at agricultural research farm of BHU, Varanasi, to study the effect of different tillage practices and green manuring on productivity and profitability of maize-wheat cropping system. The experiment was laid out in split plot design comprising 20 treatments. The four different tillage practices, viz. T1 (Conventional tillage maize-Conventional tillage wheat), T2 (Minimum tillage maize-Minimum tillage wheat), T3 (Minimum tillage maize-Zero tillage wheat) and T4 (Zero tillage maize-Zero tillage wheat) were assigned to main plot and five summer green manuring treatments, viz. M1 (Summer fallowing), M2 (Dhaincha), M3 (Sunnhemp), M4 (Clusterbean) and M5 (Cowpea) were kept in sub plots. The treatment, T4 and T1 were at par with each other and registered higher yield attributing characters, grain (4814.61, 4931.94 and 4754.03, 4840.69 kg/ha during 2016–17 and 2017–18, respectively) and straw yield, quality and B:C ratio. In case of summer green manuring, M2 (Dhaincha) recorded higher yield attributing characters, grain and straw yield and quality (4846.27, 4957.54 kg/ha during 2016–17 and 2017–18, respectively) over other treatments but it was at par with M3 (Sunnhemp). It is recommended that ZT wheat and summer green manure Dhaincha residue mulching should be followed to achieve higher yield and profitability.

The effects of different tillage practices on soil properties, yield and pest incidence of various sweet corn (Zea mays L. Var Saccharata) varieties

Conservation tillage is one of the crop production adaptation strategies for conserving soil and mitigating climate change. This study aimed to evaluate the effects of different tillage practices on the yield, soil properties, and pest incidence of corn varieties that would give optimum output. The experiment was laid out in a split-plot arranged in a randomized complete block design with three replications. Zero and minimum tillage served as the main plot, and the different sweet corn varieties as the subplot (T1-Macho F1, T2-Sweet Supreme F1, T3-Purple Magic F1, T4-Hi-Brix XL F1, and T5-Sugar King F1). Results showed that Hi-Brix XL F1 (8t ha-1), Purple Magic F1 (7.44t ha-1), and Macho F1 (7.45t ha-1) obtained high marketable ear yields among the different sweet corn varieties. On the other hand, zero and minimum tillage did not vary significantly in terms of the soil properties, resulting in no yield advantage for sweet corn. This means that sweet corn production can be done either with zero or minimum tillage. In addition, zero tillage practice obtained lower fresh weight (g) of weeds at 15 and 45 days after planting. Weeds were eliminated using non-selective herbicide spray with zero tillage, resulting in lower weed incidence than with minimum tillage where only one plowing and harrowing were done.

Effects of tillage on soil nitrogen and its components from rice-wheat fields in subtropical regions of China

It is of great significance to explore the effects of different tillage practices on total nitrogen and its components in rice-wheat rotation farmland. The experiment was carried out in Jiangyan County, Jiangsu Province of China, and a total of four treatments were set up: minimum tillage (MT), rotary tillage (RT), conventional tillage (CT), and conventional tillage without straw retention (CT0). The total nitrogen (TN), light fraction nitrogen (LFN), heavy fraction nitrogen (HFN), particulate nitrogen (PN), and mineral-associated nitrogen (MN) in 0-20 cm soil were determined. The results show that MT increased TN concentration by2.26%-27.57% compared with the other treatments in 0-5 cm soil, but it lost this advantage in 5-10 cm and 10-20 cm soil. MT altered the concentration of LFN by 6.03%-95.86%, of HFN by 1.68%-20.75%, of PN by 12.58%-96.83%, and of MN by −1.73%-9.83% as compared to RT, CT, and CT0 in 0-5 cm soil, respectively. With the deepened of soil depth, the concentration of TN, LFN, HFN, PN, and MN decreased quickly in MT, which was lower than that in RT and CT at 10-20 cm soil depth. Straw return increased the concentration of TN and its components in 0-20 cm soil. The concentration of TN was extremely significantly positively correlated with that of LFN, HFN, PN, and MN (p<0.01). The variation of TN was significantly positively correlated with that of LFN, HFN, PN, and MN (p<0.01), and LFN showed the highest sensitivity to tillage practice. In general, minimum tillage combined with straw retention increased the concentration of soil TN and its components in topsoil. LFN was the best indicator to indicate the change in soil total nitrogen affected by tillage practice. Keywords: rice-wheat rotation, soil active nitrogen components, light fraction nitrogen, heavy fraction nitrogen, particulate nitrogen, mineral-associated nitrogen DOI: 10.25165/j.ijabe.20221503.5661 Citation: Cui S Y, Zhu X K, Cao G Q. Effects of tillage on soil nitrogen and its components from rice-wheat fields in subtropical regions of China. Int J Agric & Biol Eng, 2022; 15(3): 146–152.

Effects of subsoiling rotational patterns with residue return systems on soil properties, water use and maize yield on the semiarid Loess Plateau

In recent years, conservation rotational tillage has been proposed to regulate soil physicochemical properties and improve soil productivity. However, the response of soil productivity to different rotational tillage with residue return systems remains unclear. Based on this concept, a long-term experiment (2007–2019) concerning conservation rotational tillage with residue-returned was established with four tillage treatments: (1) no-tillage was set at the first year, conventional tillage was set at the second year, and the third year was set with subsoiling (NCS); (2) the first year was set with no-tillage then rotated with subsoiling in the second year (NS); (3) the first year was set with subsoiling then rotated with conventional tillage in the second year (SC); (4) subsoiling (S) was set each year as the control, and all tillage took place after the residue return. After a 12-year in situ tillage experiment, NCS and SC significantly reduced soil bulk density (BD) by 7.4 % and 13.2 %, respectively, and increased soil porosity by 8.8 % and 14.6 %, respectively, in the 0−20 cm soil depth. Meanwhile, NCS, NS and SC increased the macroaggregates by 27.4 %, 22.4 % and 30.0 %, respectively, at the 0−40 cm soil depth, and NCS significantly increased aggregate stability compared with S. For the effect of different tillage practices on soil nutrients, SC slight increased annual average soil organic (SOC) and total nitrogen (TN) by 4.5 % and 7.2 % compared with S. In addition, the soil water balance showed a negative trend of consumption, but NCS, NS and SC mitigated water consumption at the 0−200 cm soil depth, especially in dry years. The 12-year spring maize cultivation consumed soil water storage at a 120−420 cm soil depth, especially in ST, which increased this factor by 28.7 %–34.1 % when compared with others. In normal year, NCS significantly increased yield by 3.7 %–10.4 % compared with others. Considering the effect of the long-term experiment, NCS increased the annual average yield, WUE and PUE by 5.2 %, 4.7 % and 5.6 % compared with S, respectively. Based on the comprehensive Z-index score, the NCS with residue return was selected as the recommended agricultural management measure suitable for the climate-similar region of the Loess Plateau.

Effects of different tillage practices on rill distribution of sloping farmland

AbstractTo better understand how surface roughness affects soil erosion, we investigated the rill distribution of sloping farmland under tillage practices in China's Loess Plateau region. Four tillage treatments (three tillage practices and a non‐tillage control) were simulated manually using five slope gradient levels (3°–20°) and two rainfall intensities (90 and 120 mm h–1). The spatial distribution of rills was extracted and four indices were derived based on Strahler's stream ordering. With increasing slope gradient, random roughness exhibited a decreasing effect on sediment yield, and the interaction effect changed from negative to positive at a critical slope gradient of ∼10°. Low‐order rills gradually merged into high‐order rills, forming a complete rill network toward higher slope gradients. The bifurcation ratio of different treatments did not differ considerably. With increasing surface roughness, the length of first‐order rills and their longitudinal river slope decreased. For example, on the 10° slope under 90 mm h–1 rainfall intensity, the longitudinal river slope of contour plowing, manual hoeing, and contour drilling treatments decreased respectively by 29.4, 38, and 48.9% relative to the value of smooth surface (control) with a rise in rill order. Yet a greater surface roughness had the least effect on the number, length, and longitudinal river slope of third‐order rills. A similar result was obtained in that correlation between sediment yield and the length of third‐order rills was the weakest overall. The results indicate that surface roughness affects rill distribution and soil erosion on sloping farmland via its effect upon low‐orderrill development.

Effects of Different Tillage Practices and Cropping Patterns on Soil Physical Properties and Crop Productivity

A series of experiments using nine treatment combinations comprising three tillage practices (zero tillage, conventional tillage and deep tillage) and three cropping patterns (wheatfallow- T. aman, wheat–mungbean-T. aman and wheat-dhaincha-T. aman) were examined in a split- plot design at Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh during 2008-2009 and 2009-2010 to study the effect of different tillage practices and cropping patterns on soil physical properties and crop productivity in a previously puddled soil. Soil physical properties viz. bulk density, particle density and porosity showed insignificant result due to tillage practices and cropping patterns but soil moisture retentive properties demonstrated significant outcomes. Deep tillage with dhaincha (Sesbania rostrata) and mungbean (Vigna radiata L. Wilczek) biomass incorporation conserved moisture in the soil profile and improved other soil physical properties i.e. reduced the bulk density, increased porosity and available water content of soil. The highest grain yield of wheat and rice was recorded in the deep tillage with wheat-dhaincha-T. aman cropping pattern and lowest in zero tillage with fallow based cropping pattern.

Weed shift and community diversity in conservation and conventional agriculture systems in pigeonpea- castor systems under rainfed semi-arid tropics

Conservation agriculture (CA) is an alternative sustainable production system to conventional tillage system for resource conservation in rainfed agriculture. Weeds are the major constraints for adoption of CA in rainfed regions. A seven years study was done at ICAR- Central Research Institute for Dryland Agriculture (CRIDA), Hyderabad, India, to study the effects of different tillage practices and residue levels on weed shift, diversity and crop yields. It was observed that annual weed species were dominant in conventional tillage (CT) and reduced tillage (RT), whereas a shift towards perennials was observed in zero tillage (ZT). The CT recorded significantly lower weed density and weed biomass (12.89 m−2 and 35.60 g m−2) over RT (17.33 m−2 and 38.37 g m−2) and ZT (36.67 m−2 and 69.58 g m−2) after seven years, respectively. A shift in weed species, higher weed density and weed biomass in dicots (Tridax procumbens L and Euphorbia hirta L. and a marginal decrease in monocots (Bulbostylis barbata, Digitaria sanguinalis L) was observed in ZT. The marginal decrease in monocots was due to higher precipitation immediately after herbicide application which reduced the control of weeds due to leaching. The anchored residues 10 and 30 cm recorded lower monocots and total weed count over No residue. The study suggests that integrated weed management (combination of herbicide and removal of chance weeds) and in RT are efficient strategies to minimise the weed infestation in CA and these methods not only reduce the over reliance on herbicides but also improve the productivity of pigeon pea (Cajanus cajan L.), castor (Ricinus communis) and the environmental performance of CA. ZT and RT recorded the highest Shannon index, Pieloús evenness index and species richness over CT which indicates a higher weed species diversity in ZT as compared to CT. This study helps to improve the understanding of crop–weed communities and in the development of cost effective environmentally sound weed management strategies.