Effects of Tillage Methods on Ammonia Volatilization of Early Season Rice-ratooning Rice Fields

Soil management practices, such as tillage method or straw return, could alter soil organic carbon (C) contents. However, the effects of tillage method or straw return on soil organic C (SOC) have showed inconsistent results in different soil/climate/cropping systems. The Yangtze River Delta of China is the main production region of rice and wheat, and rice-wheat rotation is the most important cropping system in this region. However, few studies in this region have been conducted to assess the effects of different tillage methods combined with straw return on soil labile C fractions in the rice-wheat rotation system. In this study, a field experiment was used to evaluate the effects of different tillage methods, straw return and their interaction on soil total organic C (TOC) and labile organic C fractions at three soil depths (0–7, 7–14 and 14–21 cm) for a rice-wheat rotation in Yangzhong of the Yangtze River Delta of China. Soil TOC, easily oxidizable C (EOC), dissolved organic C (DOC) and microbial biomass C (MBC) contents were measured in this study. Soil TOC and labile organic C fractions contents were significantly affected by straw returns, and were higher under straw return treatments than non-straw return at three depths. At 0–7 cm depth, soil MBC was significantly higher under plowing tillage than rotary tillage, but EOC was just opposite. Rotary tillage had significantly higher soil TOC than plowing tillage at 7–14 cm depth. However, at 14–21 cm depth, TOC, DOC and MBC were significantly higher under plowing tillage than rotary tillage except for EOC. Consequently, under short-term condition, rice and wheat straw both return in rice-wheat rotation system could increase SOC content and improve soil quality in the Yangtze River Delta.

Strip rotary tillage seeding technology has been widely used in rice–wheat rotation system, benefiting the economy greatly. The purpose of farming is to create a comfortable seedbed environment for crop growth. Therefore, it is necessary to consider the effects of tillage methods on wheat root configuration and growth trend in the research of strip tillage, instead of just focusing on optimizing the shape of tillage tools, sowing methods, and soil fragmentation. To clarify the effects of different tillage methods on crop root growth trends, a two-year wheat planting experiment was carried out. Strip tillage (ST1 and ST2) and full width tillage treatment (FT) were designed, 3D models of root structure and soil on the surface of the seedbed wall were established, and four quantitative indexes were proposed: soil surface roughness of seedbed wall (SR), difference coefficient of root soil space occupation (P), difference coefficient of root angle expansion trend (PA), and difference coefficient of root length expansion trend (PL). The results showed that the cultivation method directly affects the growth trend of wheat roots. The wheat roots tended to grow along the inter-specific direction under ST treatment on the 14th day, and the average P, PA, and PL were as high as 38, 43, and 55, respectively. The SR produced by ST1 treatment was 70% lower than that of ST2 treatment, suggesting ST1 treatment had more serious restrictions on root growth. P, PA, and PL in ST1 treatment were 38.5%, 14%, and 43% higher than those in ST2 treatment within 14 days, respectively. This paper briefly explains the effects of tillage methods on the growth trend of wheat roots, provides new methods and technologies for the rapid and effective acquisition of soil surface information, solved the problem of the trend of root expansion being difficult to quantify, and provided a new direction for the optimization of tillage methods.

Fungus growing termites, Microtermes sp. and Odontotermes sp. are important pests of maize in southern Africa. They damage roots and stems of maize plants and cause lodging of plants after senescence. Termite nests are difficult to locate and destroy and no effective method of control has yet been developed. Different tillage methods that could destroy nests were evaluated in the field over two seasons. Tillage methods included deep chisel plough, shallow chisel plough, deep mouldboard plough, rip and rip-on-row. Significant differences were observed in the effect of different tillage methods on lodging of maize plants. The deep mouldboard plough treatment that disturbed and overturned soil to a depth of 0.30 m resulted in significant reduction in incidence of lodged plants. The deep chisel treatment disturbed the upper 0.25 m soil layer and also resulted in a significant reduction in the incidence of lodging. The shallow chisel and rip-on-row treatments had the highest incidence of lodging. Deep tillage methods are, however, not considered to be a long-term solution for termite damage in maize.

Tillage is one of the most important practices affecting soil physical and hydraulic properties. Its effects may vary intensely according to the tillage method. This study aims to evaluate the effects of different tillage methods (moldboard plow+disk harrow, moldboard plow+rotary tiller and chisel plow+disk harrow) and drainage (subsurface drainage and non-drainage) on soil physical properties in a clay loam soil. The experiment was conducted in split-plot in time statistical design. Soil bulk density, aeration porosity, organic matter, aggregate mean weight diameter (MWD) and water infiltration rate were measured after planting and after harvesting of winter-wheat crop. Results revealed that the tillage method had significant effect on organic matter content, such that the lowest (1.18%) and highest (1.35%) values were observed in moldboard plow/disk harrow and chisel treatment, respectively. Tillage effect was significant on saturated moisture content, MWD, aeration porosity and infiltration rate. The effect of time was significant on all investigated factors. The effect of drainage was significant on MWD and infiltration rate. Evaluating the interaction effect of tillage and drainage indicated that the contribution of drainage on changing MWD is higher than the tillage methods. Further, it was concluded that the selection of tillage method had an important role on aeration porosity and MWD in no drainage condition, so that moldboard plow makes much more aeration porosity (25.48% against 17.17%) and less MWD (2.40 against 2.80 mm) compared to chisel. According to the result, the treatment combination including drainage/after planting/moldboard plow and disk harrow had the lowest MWD and also, combined treatment of no drainage/after harvesting/chisel plow) had the highest MWD. The application of chisel is not recommended in no-drained areas having high level of groundwater, because of the highest saturated moisture content and MWD along with the lowest aeration porosity compared to moldboard plow.

The experiments on the effects of different tillage method (Flat, Bed and Trench) on the yield of egg plant (Solanum macrocarpon ) were conducted at School of Agriculture and Agricultural Technology (SAAT) Training and Research farm, Federal University of Technology Owerri, (FUTO), Imo State Nigeria. The result showed that plant heights of Solanum macrocarpon increased with age of the plant. The apices cutting technique helped to increase the number of branches per plant and the bed tillage method performed significantly better than the flat and trench methods in flower set , fruit set and development. However, tillage methods are location specific and vary with climate, soil type, and crop and management level.

This research was conducted between 2011 and 2015 at research field of Faculty of Agriculture, Eskişehir Osmangazi University for evaluating two tillage methods (conventional and reduced), three crop rotations (wheat-wheat; wheat-fallow; wheat-chickpea) and four N levels (0, 50, 100, 150 kg ha-1). The experimental design was split-split plot with three replicates. Tillage methods were in main plots, crop rotations in subplots and N levels in sub-sub plots. The N concentration of grain and straw harvested from aboveground plant organs was separately determined using by the Kjeldahl digestion method after the plant samples were ground. Then, grain protein content, nitrogen use efficiency (NUE), nitrogen uptake efficiency (NUPE), nitrogen utilization efficiency (NUTE) were calculated. According to results, effects of tillage methods on NUE were unclear. Conventional tillage methods resulted in higher NUPE than reduced tillage in the last three years of the experiment. The NUTE was higher in reduced tillage than conventional in 2011-2012 and 2014-2015. The effects of tillage methods on grain yield were different due to the climatic conditions. Wheat-chickpea rotation had the better results for examined traits in this research. Increasing nitrogen doses increased grain and plant protein rate, however it decreased NUE and NUPE. The effects of nitrogen doses on NUTE were ambiguous. Nitrogen use efficiency and NUPE is traits that can be differed according to changeable grain yield depend on environmental conditions. Therefore, the experiments should be conducted for more than four years for revealed absolute effects both soil tillage method and nitrogen fertilization.

Effect of tillage method on carbon-dioxide emission andsoil properties under two soil surface levels

Biaxial rotary tillage is considered an effective approach for enhancing the structure of soil in rice fields. There are few reports on the effects of biaxial rotary tillage on the carbon footprint (CF), energy budget, and net ecosystem economic efficiency (NEEB) of rice fields. Here, we evaluated the effects of dryland biaxial rotary tillage (DBRT), as well as two traditional tillage methods, dryland and paddy field in uniaxial rotary tillage (DPURT) and paddy field in uniaxial rotary tillage (PURT), on the CF, energy budget, and NEEB of rice production to clarify the economic and ecological utility of DBRT. The tillage depth was 9.5–15.4% higher under DBRT than under DPURT and PURT (p < 0.05). The soil bulk density was 5.4–12.1% lower under DBRT than under DPURT and PURT. The rice grain yield was 7.6–8.7% and 17.7–19.1% higher under DBRT than under DPURT and PURT, respectively (p < 0.05). The total global warming potential was 7.6–10.6% and 17.0–20.4% lower under DBRT than under DPURT and PURT, respectively (p < 0.05). The CF was 17.7–18.9% and 35.4–36.1% lower under DBRT than under DPURT and PURT, respectively. The energy use efficiency was 8.7–10.4% and 16.4–18.3% higher under DBRT than under DPURT and PURT, respectively. The NEEB were 13.2–15.7% and 28.6–32.1% higher under DBRT than under DPURT and PURT, respectively. In summary, DBRT is beneficial for increasing rice yield and reducing greenhouse gas emissions, thereby improving the economic and ecological benefits of rice.

Different tillage methods can have varying effects on soil properties and crop quality. Therefore, field experiments were conducted at the Teaching and Research Farm of Landmark University, located in Omu‐Aran, Kwara State. The objectives were to investigate the impacts of various tillage methods on soil characteristics and the growth, yield, mineral and proximate content of soybean (Glycine max (L.) Merr.). Based on these objectives, it was hypothesized that soil properties, growth, yield, mineral and proximate contents of soybean would react differently to different tillage methods. Consequently, experiments were conducted to validate this hypothesis. The treatments were four tillage methods: manual clearing (MC), ploughing (P), ploughing plus harrowing (P + H) and manual ridging (MR), replicated three times in a randomized complete block design. Data on the initial soil properties (bulk density, particle size, pH, organic matter, N, P, K, Ca and Mg), along with the chemical properties of the soil on a per‐plot basis at the end of the experiment, were collected. Additionally, data on soil bulk density, porosity, moisture content and temperature were collected during the vegetative growth of the soybean. Soybean plant height and the number of branches were recorded at the midflowering stage, while grain yield and the number of pods were recorded at harvest. Soybean seeds were later analysed for their mineral and proximate contents using standard methods. P + H resulted in lower soil bulk density than other tillage methods and led to higher growth, yield, proximate and mineral contents of soybean. In MC, bulk density, soil moisture content, soil organic matter, N, P, K, Ca and Mg were significantly higher and temperature lower than in other tillage methods; yet, these advantages did not translate into increased yield and quality due to the higher bulk density. The growth, yield and quality of soybean were significantly influenced by soil bulk density rather than by soil chemical properties. Using the mean of the two sites, relative to MC, P and MR, P + H increased the grain yield of soybean by 41.3%, 24.4% and 13.7%, respectively. These findings underscore the importance of appropriate tillage practices for successful soybean cultivation in similar agroecological zones. For small‐scale operations, MR is suggested, while P + H is recommended for large‐scale soybean production in the studied area. Future studies could include additional variables, such as economic analysis, long‐term soil health impacts or the effects of tillage methods under varying climate conditions.

A two-year research was conducted to investigate the effect of different tillage methods on some soil physical characteristics and crop yield in rapeseed cultivation after rice harvesting. Five tillage treatments including: (i) using rotavator, once to depth of 10-15 cm (T1), (ii) using rotavator, twice to depth of 10-15 cm (T2), (iii) using moldboard plow to depth of 25 cm + rotavator, once to depth of 10-15 cm (T3), (iv) no-till planting through removing rice stubbles from plots (T4), and (v) no-till planting without removing rice stubbles from plots (T5), were evaluated under randomized complete block design (RCBD) in three replications. The biannual results revealed that the effect of tillage methods was significant (p<0.01) on soil bulk density, surface residues after tillage, dry mass of weeds, seed germination, and grain yield. T2 and T3 made considerable reduction in soil bulk density compared to other treatments for the 15- to 30-cm tillage depths. In T1, T2, T3, and T4, surface residues after tillage decreased in comparison with T5 by up to 35.37, 50.71, 69.92, and 75.75%, respectively. Having 71.48 g m-2, T5 had the maximum dry mass of weeds while T3 had the minimum one with 37.50 g m-2. Means comparison represented that in T2 and T3, seed germination reached the shortest length of 6.4 days in average. The highest and lowest grain yields were acquired in T3 (1,571 kg ha-1) and T5 (1,339 kg ha-1), respectively. Statistically, there was no significant difference between T1 (1,432 kg ha-1) and T2 (1,537 kg ha-1) compared with T3 in terms of grain yield.

To standardize the tillage methods and dates of direct seeded Jammu Basmati rice varieties under sub tropical condition, a field experiment was conducted at research farm of Agrometeorology Section, Division of Agronomy, SKUAST-J, Chatha, Jammu during kharif season 2020. The experiment was comprised of two tillage methods i.e. zero (T1) and conventional tillage (T2) , two direct sowing dates viz., 10th (D1) and 25th June (D2) along with four newly released Basmati rice varieties viz., Jammu Basmati-370 (V1), Jammu Basmati-118 (V2), Jammu Basmati-138 (V3) and Jammu Basmati-123 (V4) with 16 treatment combinations and three replications in split-split plot design. Various crop growth parameters (plant height, LAI and above ground dry matter accumulation) were recorded at fortnight interval starting from 30 DAS till physiological maturity of crop was attained. Jammu Basmati rice varieties sown under conventional tillage method recorded significantly higher number of tillers/m2 (232.7) and also effective tillers/m2 (222.7) than the zero tillage method. The 10th June sown crop observed significantly higher leaf area index, dry matter accumulation, yield and yield attributes compared to late sown crop. Crop sown under conventional tillage method realized significantly higher grain yield (23.74 q/ha) as compared to zero tillage method (18.03 q/ha). Among the varieties, Jammu Basmati-123 recorded significantly higher leaf area index, dry matter accumulation and grain yield followed by Jammu Basmati-118, Basmati-370 and Jammu Basmati-138.

A 3 year (1976-1978) tillage study was conducted with snap beans (Phaseolus vulgaris L.) and lima beans (P. lunatus L.). Treatments included 2 no-till systems where furrows were opened with a fluted coulter or a vibratory unit, 2 reduced tillage methods with seedbeds prepared with a disk or a powered harrow, and conventional tillage. Tillage method did not affect soil pH at sampled depths. Soil P levels were higher at the 10−15 cm depth with conventional compared to tillage with vibratory unit. Soil K levels were higher at the 5−10 and 10−15 cm depths with conventional tillage. Tillage method did not affect petiole N, K, and Ca concentrations. Petiole P concentrations were lowest with conventional tillage. Petiole Mg concentrations were lowest with the no-till treatments using fluted coulter for snap beans and the vibratory unit for lima beans. Snap bean stand was highest with no-till using the vibratory unit. Tillage method did not affect mean snap bean yield or lima bean stand. Mean lima bean yield was highest with conventional tillage.

The effect of tillage methods and rates of wood ash on soil chemical properties and castor bean plant performance was studied in field trial at Abakaliki in three planting seasons. The experiment was a split plot in randomized complete block design with three tillage methods (mound, ridge, flat) and four rates of wood ash (0, 2t, 4 and 6 tha-1) replicated three times. Crop start version 7.2 was used to analyze data collected and mean separation was done using least significant difference (LSD) at 5% alpha level. The results of soil pH and available P showed that tillage method (TM) increased the values of the nutrients in 2nd year, but decreased in the 3rd year planting. The values of these parameters observed in Ridge method was found to be higher when compared to the values of Mound and Flat except for the result of available P in 1st  and 3rd year planting periods. The wood ash (WA) amendment was found to change the soil from slightly acidic in 1st year to alkaline in 2nd year to slightly acidic in 3rd year. The control soil remained acidic throughout the three years of study. The available P obtained from Rd6 consistently gave the highest values among the TM and rates of WA. Tillage methods had no effect on leaf area index (LAI) at 50 days after planting (DAP) and 100 DAP in 1st and 2nd year planting periods, but had significant effect on the parameters in 3rd year planting season. Flat showed highest plant height in 1st and 2nd years but decreased in the 3rd year. While the least value in plant height for the 3 years’ of study was recorded in Mound. The findings from this study has clearly shown that soil application of wood ash and tillage practices has the potential to cause positive and useful changes in the fertility and productivity status of the soil by improving the soil properties and yield component of castor.   Key words:  Ash, available P, castor plant, leaf area, plant height, soil reaction, tillage.

Summer rice fallows are the potential areas for crop diversification with millets. A field experiment was conducted at Integrated Farming System Research Station (IFSRS), Karamana during summer season of 2023-24 with an objective to find out the effect of tillage method and establishment method on weed dynamics and soil health. The field experiment was laid out in split-split plot design with 12 treatment combinations and three replications. The main plot treatments were tillage method (M1-minimum tillage and M2 - conventional tillage), sub plot treatments were crops (C1-little millet, C2-foxtail millet and C3-proso millet) and the sub-sub plot treatments were establishment methods (P1- solid row planting and P2- broadcasting). The study indicated that grasses were the predominant weed flora in summer fallows and the lowest weed density and weed dry weight were observed in conventional tillage method with solid row planting. Among the establishment method, the highest N, P and K removal by weeds was recorded in broadcasting method (134.52 kg ha-1, 4.38 kg ha-1 and 10.29 kg ha-1, respectively). The results revealed that the highest organic carbon (2.09%) was recorded in minimum tillage. The highest available N and P were recorded in minimum tillage and solid row planting. From the study it could be concluded that minimum tillage with solid row planting enhanced the soil health while conventional tillage with solid row planting is a viable option for weed management of small millets in summer rice fallows.

Tillage methods and mulch influences the productivity and water requirement of spring maize hence a field experiment was conducted at the National Maize Research Program, Rampur in spring seasons of 2011 and 2012 with the objectives to evaluate different tillage methods with and without mulch on water requirement and grain yield of spring maize. The experiment was laid out in two factors factorial randomized complete design with three replications. The treatments consisted of tillage methods (Permanent bed, Zero tillage and Conventional tillage) and mulch (with and without). Irrigation timing was fixed as knee high stage, tasseling stage and milking/dough stage. Data on number of plants, number of ears, thousand grain weight and grain yield were recorded and analysed using GenStat. Two years combined result showed that the effect of tillage methods and mulch significant influenced grain yield and water requirement of spring maize. The maize grain yield was the highest in permanent beds with mulch (4626 kg ha-1) followed by zero tillage with mulch (3838 kg ha-1). Whereas total water applied calculated during the crop period were the highest in conventional tillage without mulch followed by conventional tillage with mulch. The permanent bed with mulch increased the yield and reduced the water requirement of spring maize in Chitwan.