Reduced Tillage Research Articles

How do conventional and organic management affect the healthy potential of durum wheat grain and semolina pasta traits?

The effect of cropping system (conventional vs. organic) and soil tillage (conventional vs. reduced tillage) on the health potential of durum wheat grain as well as on semolina and pasta quality traits was investigated in a long-term field experiment. Total antioxidant capacity, total arabinoxylans, alkylresorcinols, yellow pigments and total phenolics, which were assessed in kernels, revealed differences between the two cultivation systems only in 2011, whereas in the 2010 rainy season, cropping management did not influence these compounds. Proteins and W index were higher in the conventional system, except for the exceptionally rainy years. In contrast, the quality of cooked spaghetti was comparable in both management systems. Soil tillage differently affected bioactive compounds but had no impact on semolina and pasta quality. Overall, climatic conditions was the major factor affecting the quality of durum wheat. Our results indicate that an organic system does not represent a constraint to obtaining durum wheat grain with healthy potential relative to conventional wheat.

Is it feasible to reduce tillage and N use while improving maize yield in irrigated Mediterranean agroecosystems?

Abstract Mediterranean rainfed areas are transformed into irrigation to stabilize or increase crop yields. The gradual occupation of irrigation leads to an increase in nitrogen use and intensity of tillage. The aim of this work was to evaluate the combined impact of tillage systems and mineral N fertilization rates on maize grain yield, water and nitrogen use efficiencies (WUE and NUE) under Mediterranean irrigated conditions. The study was carried out in NE Spain during three maize growing seasons (i.e. years 2015, 2016 and 2017). A long-term (LTE) tillage and N rate field experiment established in 1996 under rainfed conditions was transformed into irrigation with maize (Zea mays L.) monocrop as cropping system in 2015. Three types of tillage (conventional tillage, CT; reduced tillage, RT; no-tillage, NT) and three mineral N fertilization rates (0, 200, 400 kg N ha−1) were compared. In 2015, an adjacent experiment (short-term experiment, STE) with the same layout was set up in an area previously managed under long-term rainfed NT for the last 21 years. In the long-term tillage and N fertilization combination (LTE), the reduction of tillage (NT and RT) led to greater grain yield when applying 200 and 400 kg N ha−1 compared to the use of the same rates under CT. Differently, in the sort-term experiment with preceding NT (STE), tillage systems did not influence grain yields, while N application led to greater yields than the control (0 kg N ha−1). In both situations (LTE and STE), NT and RT enhanced soil water content before planting leading to greater crop growth compared to CT. The lack of available water under CT caused lower maize stover, yield, and yield components in LTE and, therefore, lower WUEB (for biomass) and WUEY (for yield). In LTE, the use of long-term CT led to a significant accumulation of nitrate compared to NT. Differently, in the STE, soil nitrate content did not show differences between tillage systems. In the LTE, water and N were used more efficiently to produce aboveground biomass and grain yield in RT and NT. Our study shows that in Mediterranean agroecosystems transformed into irrigation the use of NT and RT with medium rates of N leads to greater maize yield, WUE and NUE than the traditional management based on CT with high rates of mineral N. In rainfed areas with long-term history of no-till, this soil management system can be successfully maintained if transformed into irrigation.

Some selected physical and chemical attributes of a Ustalf under different tillage practices at Dutse, Jigawa State Nigeria.

Different tillage practices are being employed by the farmers of Jigawa state, and as such, there is a need to determine its influence on some physical and chemical properties, so that farmers will base their choices on scientific facts rather than assumptions. An experiment was conducted to investigate the effects of three tillage practices (TP) on soil properties in Federal University Dutse, Teachings and Research farm, Jigawa State. The TP adopted are conventional tillage (CT), reduced tillage (RT) and zero-tillage (ZT). Samples were collected at a depth of 0 -20 cm for the chemical and other physical properties determination, while core samplers were used for bulk density (Bd) determination. All data collected were analyzed using Statistical Analysis Software (SAS and analysis of variance (ANOVA) was used to determine the significant tillage effect on the parameters measured at 5% level of significance and the means were separated using Least Significance Difference (LSD). The results showed that the soil texture of the study area was sandy loam. ZT differed significantly from other TP with higher Bd value of 1.51 Mg m-3, lower porosity (42.7%), and lower moisture content (10.3). ZT also had higher organic carbon (OC), total nitrogen (TN), available phosphorus (AP), exchangeable acidity (0.48 cmol+ kg-1) and bases and most importantly higher CEC (7.5 cmol (+) kg-1) which differed significantly from other tillage practices and the lowest of the most parameters were found in RT. Conclusively, ZT is the best TP to be used by the farmers because of the im- proved physical and chemical parameters and been not only economically sus- tainable but also socially and environmentally friendly.

Inter & Active Effect of Tillage and Nitrogen Fertilizer on Maize (Zea mays L.) Performance on a Humid Alfisol Southwestern, Nigeria

A field trial was conducted in 2017 to investigate the interactive effect of the land preparation methods and different rates of nitrogenous fertilizer on maize performance and yield southwestern Nigeria. The experiment was a 3 by 3 factorial; conducted in a Randomized Complete Block Design (RCBD) in a split plot management with tillage systems (T): Convectional tillage (CT), Reduced tillage (RT) and No-tillage (NT) as the main plot while nutrient amendments (N) rates (0, 50, and 120 Kg N.Ha-1) as sub-plots factor and all treatments were replicated three times. Growth and yield parameters were subjected to analysis of variance (ANOVA). No tillage had the least plant height, stem diameter and stover weight but had the highest grains yield. Grain yield were not statistically different in all the tillage practices at different N rates applied but 60 kg N ha-1 seems best for maize production in the study area.

Effects of conventional moldboard and reduced tillage on seasonal variations of direct CO2 and N2O emissions from a loam Haplic Luvisol

Greenhouse gases such as N2O and CO2 are formed in microbiological processes of nitrification and denitrification and also governed by microbial decomposition of soil organic matter (SOM) plant residues. A key factors influencing these processes are temperature and soil moisture. Therefore the objectives of this study were to: (1) evaluate the seasonal variations in SOM content, temperature, water-filled pore space (WFPS) and mineral nitrogen content under conventional tillage (CT) and reduced tillage (RT) system, and (2) assess the direct CO2 and N2O emissions associated with the seasonal variations in the soil properties under both tillage systems. An experiment was carried out in a randomized blocks with two different tillage system: CT and RT in a Haplic Luvisol (loamy) covering the growing season of spring barley. Each block included treatments: no mineral fertilizers; mineral fertilizers; mineral fertilizers plus plant residues. Overall, the SOM content and temperatures were insignificantly higher in the plough layers of RT than CT during the entire period of study. Soil moisture content (SMC) and WFPS were insignificantly higher in CT than RT. The application of mineral fertilizers resulted in a significant increase of mean NO3− concentrations only in the plough layers of CT. SMC was a stronger driving factor of mean daily CO2 emissions in all treatments, while variations in soil temperatures and SMC were jointly responsible for changes in mean daily N2O emissions in all the treatments of CT and RT. The postponed highest peaks of mean daily N2O emissions from RT were observed under aerobic soil conditions several days after the heavy rainstorm. The cumulative CO2 and N2O fluxes were insignificantly higher from CT than RT over the entire period of study.

Cover crops and compost prevent weed seed bank buildup in herbicide-free wheat-potato rotations under conservation tillage.

Weeds are a major constraint affecting crop yields in organic farming and weed seed bank analysis can be an important tool for predicting weed infestation and assessing farming system sustainability.We compared the weed seed banks two and four years after transition from conventional to reduced tillage in organically managed winter wheat–potato cropping sequences in two replicated field trials. Experimental factors were either conventional (CT) with moldboard (25 cm) or reduced tillage (RT) with chisel ploughing (5–15 cm). Dead mulch (8–10 cm), consisting of rye–pea or triticale–vetch mixtures, was additionally applied to potatoes in the RT system. In both systems, one‐half of the plots received 5 t (ha/year) dry matter of a commercially sold yard waste compost as an organic amendment. Furthermore, subsidiary crops were grown in both systems, either as legume living mulches undersown in wheat or as cover crops sown after wheat. Prior to sowing the wheat and after potatoes, the soil seed bank from 0 to 12.5 and from 12.5 to 25 cm was sampled and assessed in an unheated glasshouse over nine months.The initial weed seed bank size in the topsoil was uniform (4,420 seedlings m−2). Two years later, wheat‐associated weeds, such as Galium aparine, Lamium spp., and Myosotis arvensis, were 61% higher on average in RT than in CT. This was independent of subsidiary crops used. In contrast, Chenopodium album, a potato‐associated weed that depends on intensive tillage, was reduced by 15% in the mulched RT system compared to CT. When RT was combined with cover crops and compost application, the seed bank did not differ significantly from the CT system.We conclude that subsidiary crops, mulches, and potentially compost are important management tools that contribute to the success of RT in herbicide‐free cereal‐based systems in temperate climates.

Impact of nitrogen fertilization and tillage practices on nitrous oxide emission from a summer rice ecosystem

ABSTRACTIdentification of the combination of tillage and N fertilization practices that reduce agricultural Nitrous oxide (N2O) emissions while maintaining productivity is strongly required in the Indian subcontinent. This study investigated the effects of tillage in combination with different levels of nitrogen fertilizer on N2O emissions from a rice paddy for two consecutive seasons (2013–2014 and 2014–2015). The experiment consisted of two tillage practices, i.e., conventional (CT) and reduced tillage (RT), and four levels of nitrogen fertilizer, i.e., 0 kg N ha–1 (F1), 45 kg N ha–1 (F2), 60 kg N ha–1 (F3) and 75 kg N ha–1 (F4). Both tillage and fertilizer rate significantly affected cumulative N2O emissions (p < 0.05). Fertilizer at 45 and 60 kg N ha–1 in RT resulted in higher N2O emissions over than did the CT. Compared with the recommended level of 60 kg N ha−1, a 25% reduction in the fertilizer to 45 kg N ha−1 in both CT and RT increased nitrogen use efficiency (NUE) and maintained grain yield, resulting in the lowest yield-scaled N2O-N emission. The application of 45 kg N ha−1 reduced the cumulative emission by 6.08% and 6% in CT and RT practices, respectively, without compromising productivity.

Scale effects of runoff generation under reduced and conventional tillage

Review studies indicate that conservation tillage effectively reduces runoff generation measured on large plots, but less so on smaller plots. These tillage and scale effects have never been measured in a single study for temperate mechanized agriculture. With the objective to study how runoff production changes with scale as influenced by tillage we set up rainfall-runoff plots of 5 m2, 30 m2 and 180 m2 size, on a field split into a reduced tillage (RT) and a conventionally ploughed field (CT) during two crop seasons (maize and wheat). In addition, we conducted rainfall simulations on small plots (0.7 m2) and measured soil surface properties. Average scale effects, defined as reduction of runoff coefficients with increasing plot size, were 57% (RT) and 37% (CT) between 5 m2 and 30 m2, and − 24% (reversed) (RT) and 27% (CT) between 30 m2 and 180 m2. Tillage effects, defined as the reduction in runoff coefficients of RT compared to CT were 65% at 5 m2, 86% at 30 m2 and 31% at 180 m2. On average, scale effects were 15% stronger on RT compared to CT. The overall level of runoff coefficient was most clearly affected by crop type, with winter wheat having 1.7–30 times lower runoff coefficients than maize. Crop development and soil moisture negatively affected runoff coefficients on Wheat, while rainfall intensity affected runoff coefficients positively on Maize. No evidence for interactions of these variables with either scale or tillage were found. Runoff coefficients of CT and RT diverged with scale (i.e. runoff accumulation) between 5 m2 and 30 m2, which was expected and can be explained with higher residue cover and macropore density on reduced tillage than conventional tillage slowing down runoff and increasing infiltration opportunities. Unexpectedly, between 30 m2 and 180 m2, on Maize, runoff coefficients converged strongly, which was interpreted with erosion of sealing on conventional tillage. In summary, this study confirms previous findings on the effects of tillage on runoff coefficients, but finds indications that important process transitions take place at the field scale that are affected differently by tillage, and that are not yet sufficiently studied or accounted for in models.

Effect of tillage system on the structure of weed infestation of winter wheat

The study aimed to evaluate the structure of weed infestation of winter wheat grown in different weeding systems: conventional tillage (CT), reduced tillage (RT), and herbicide treatment (HT). In CT system, shallow ploughing and pre-sow ploughing were conducted after the harvest of the previous crop. In RT system, shallow ploughing was replaced by cultivator tillage, whereas pre-sow ploughing by a tillage set. In HT system, shallow ploughing was replaced by spraying with glyphosate and pre-sow ploughing by cultivator tillage. At the tillering stage (22-23 in BBCH scale), species composition and number of weeds/m2 were determined with the botanical-gravimetric method, whereas at the stage of waxy maturity of wheat (82-83 BBCH) analyses were conducted for species composition as well as density, air-dry weight, and weed distribution in crop levels. The Shannon-Wiener’s diversity index (H’) and degrees of phytosociological constancy (S) of weeds were determined as well. The study showed that more weeds occurred in RT and HT systems than in the CT system and they produced higher biomass in RT than in CT and HT systems. The tillage system affected weed distribution in crop levels. In CT system, the highest weed density was identified in the ground and lower levels, whereas in RT and HT systems in the ground and middle levels. Values of the species diversity index (H’) indicate a similar diversity of weed species composition between weeding systems and more diverse between study years.

Soil carbon dynamics and productivity of rice–rice system under conservation tillage in submerged and unsubmerged ecologies of Eastern Indian Himalaya

Intensive tillage practices along with improper residue management in a rice (Oryza sativa)–rice system (RRS) contributed to soil fatigue and declining productivity in South Asia. Therefore, a 3-year (2013–2015) field study was conducted to assess tillage modification effects on productivity and soil C sequestration under RRS at ICAR- RC for North Eastern Hill Region, Tripura, India. The experimental site represented two different ecologies: unsubmerged (ECO 1) and submerged (ECO 2), with three tillage practices: conventional tillage (CT), reduced tillage (RT) and no-till (NT). Results showed that the cultivation of RRS under RT produced significantly higher grain (8.6–9.4 Mg ha−1) and straw (11.8–12.9 Mg ha−1) yields under both ecologies over those under CT and RT, in addition to recycling the maximum biomass. Soil under RT had lower bulk density (ρb), the highest soil organic carbon (SOC) concentration, pool, sequestration, accumulation, carbon retention efficiency, soil microbial biomass carbon and dehydrogenase activities under both ecologies as compared to CT. A total amount of 1.34 Mg C ha−1 was accumulated under soils of RT over 3 years. The rate of SOC sequestration ranged from 133.6 kg ha−1 year−1 under soils of CT to 444.7 kg ha−1 year−1 under RT in RRS. Thus, cultivation of RRS under RT with effective residue recycling is recommended for higher system productivity and C sequestration under both rice production ecologies of the NEH region of India.

Conservation agriculture effects on soil properties and crop productivity in a semiarid region of India

Conservation agriculture (CA) including reduced or no-tillage and crop residue retention, is known to be a self–sustainable system as well as an alternative to residue burning. The present study evaluated the effect of reduced tillage coupled with residue retention under different cropping systems on soil properties and crop yields in a Vertisol of a semiarid region of central India. Two tillage systems – conventional tillage (CT) with residue removed, and reduced tillage (RT) with residue retained – and six major cropping systems of this region were examined after 3 years of experimentation. Results demonstrated that soil moisture content, mean weight diameter, percent water stable aggregates (&amp;gt;0.25mm) for the 0–15cm soil layer were significantly (P&amp;lt;0.05) affected by tillage practices. Soil penetration resistance was significantly higher for RT than CT. Irrespective of soil depth, there was higher soil organic carbon (SOC) for RT than CT. The SOC fractions followed in the order: non-labile&amp;gt;moderately labile&amp;gt;less labile. At the 0–15cm depth, the contributions of moderately labile, less labile and non-labile C fractions to total organic C were 39.3%, 10.3% and 50.4% respectively in RT and corresponding values for CT were 38.9%, 11.7% and 49.4%. Significant differences in different C fractions were observed between RT and CT. Soil microbial biomass C concentration was significantly higher in RT than CT at 0–15cm depth. The maize–chickpea cropping system had significantly (P&amp;lt;0.05) higher soybean grain equivalent yield of 4.65 t ha–1 followed by soybean+pigeon pea (2:1) intercropping (3.50 t ha–1) and soybean–wheat cropping systems (2.97 t ha–1). Thus, CA practices could be sustainable management practices for improving soil health and crop yields of rainfed Vertisols in these semiarid regions.

Corrigendum to: Conservation agriculture effects on soil properties and crop productivity in a semiarid region of India

Conservation agriculture (CA) including reduced or no-tillage and crop residue retention, is known to be a self–sustainable system as well as an alternative to residue burning. The present study evaluated the effect of reduced tillage coupled with residue retention under different cropping systems on soil properties and crop yields in a Vertisol of a semiarid region of central India. Two tillage systems – conventional tillage (CT) with residue removed, and reduced tillage (RT) with residue retained – and six major cropping systems of this region were examined after 3 years of experimentation. Results demonstrated that soil moisture content, mean weight diameter, percent water stable aggregates (&amp;gt;0.25mm) for the 0–15cm soil layer were significantly (Pmoderately labile&amp;gt;less labile. At the 0–15cm depth, the contributions of moderately labile, less labile and non-labile C fractions to total organic C were 39.3%, 10.3% and 50.4% respectively in RT and corresponding values for CT were 38.9%, 11.7% and 49.4%. Significant differences in different C fractions were observed between RT and CT. Soil microbial biomass C concentration was significantly higher in RT than CT at 0–15cm depth. The maize–chickpea cropping system had significantly (P–1 followed by soybean+pigeon pea (2:1) intercropping (3.50 t ha–1) and soybean–wheat cropping systems (2.97 t ha–1). Thus, CA practices could be sustainable management practices for improving soil health and crop yields of rainfed Vertisols in these semiarid regions.

Weed density and species composition in rice-based cropping systems as affected by tillage and crop rotation

Weeds in crop fields are largely influenced by crop rotations and management practices. A better understanding of response of various weed species to changing management practices is required to develop improved weed management systems. A study was conducted to assess the effect of different tillage intensities and crop rotations on the weed population dynamics in rice- based cropping systems. In this study, three tillage practices viz. conventional tillage (CT), reduced tillage (RT) and RT with 30% crop residues (RTR30) were evaluated in three different crop rotations, viz. rice-wheat, rice-lentil and rice- winter maize for their effect on weeds. Results show that weed density and species composition differed with tillage and crop rotation. Interaction between various tillage intensities and cropping systems had significant effect on density and dry weight of total, broadleaved, grasses and sedges. Irrespective of the tillage systems rice-wheat crop rotation favoured the prevalence of weeds (a total weed population of 1670/m2 and weed dry biomass of 241.1 g/m2), whereas rice-winter maize rotation suppressed the weed growth (a total weed population of 403/m2 and weed dry biomass of 213.4 g/m2) in summer (pre- Kharif) season. Reduced tillage with 30% residues retention (RTR30) favoured the infestation of horse purslane (Trianthema portulacastrum L.) in rice-wheat cropping system, but suppressed the weed growth in rice-lentil system. Contrary to this, RTR30 favoured the infestation of black nightshade (Solanum nigrum L.) in rice-winter maize cropping system, but suppressed the weed growth in rice-lentil and rice-wheat systems during winter season.

Impact of conservation tillage and intensifying crop rotations in enhancing soil carbon, microbial cycling and aggregation in semiarid agro-eco systems: A review

Tillage influenced SOC and microbial cycling but most effects were observed at 0–5 cm rather than 5–15 cm. Reduced tillage (RT) in a continuous monoculture increased SOC by 24% compared to conventional tillage (CT) at 0–5 cm, but tillage had no effect at 5–15 cm. Crop rotation increased soil C contents compared to continuous monocropping rotation under CT increased SOC by 28% at 0–5 cm compared to CT continuous monocropping. Reduced tillage increased soil microbial biomass C (MBC) by an average of 11 and 18% compared to CT continuous monocropping and the adoption of crop rotation, respectively, while microbial biomass N (MBN) for RT was 62% greater than for CT. NT (no-till with residue) and RTW (rotary tillage with residue) treatments significantly increased the proportion of macroaggregate fractions (>2000 and 250-2000 im) compared with the MP-R (moldboard plow without residue) and MP+R (moldboard plow with residue) treatments. Averaged across all depths, mean weight diameters of aggregates (MWD) in NT and RT were 47 and 20% higher than that in MP+R. Aggregate stability in continuous rotations was about twice that in wheat-fallow rotations. Fungal biomass was three times greater in continuous rotations than wheat fallow, but was not significantly different from mid-intensity rotations.

Soil CO2 emission and short-term soil pore class distribution after tillage operations

Alongside the agricultural development in Brazil, concerns have arisen about its environmental impacts, such as the emissions of CO2 resulting from soil cultivation and management practices in agricultural production systems. The aim of this study was to investigate the temporal variation in CO2 emissions and soil physical attributes in response to the process of soil particle rearrangement after soil tillage operations. The study was conducted in three adjacent areas of 10 × 3 m, subjected to two soil tillage systems: (i) rotary hoe + conventional leveling harrow, representing an intensive soil tillage (IT); (ii) disc harrow + leveling harrow, characterizing a reduced tillage (RT). The soil of the third area was not tilled, representing the no-tillage (NT) system. Daily measurements of soil CO2 emission (FCO2), soil temperature, soil moisture, pore class distribution, bulk density, penetration resistance, water-free pore space, weighted mean diameter, aggregate stability index, total organic carbon, and particulate organic carbon were performed during a period of 29 days after soil tillage. On the first day after tillage, FCO2 was 87% higher in the plot under IT (3.86 μmol m−2 s−1) than RT (2.06 μmol m−2 s−1) and 147% higher than in the plot under NT (1.56 μmol m−2 s−1). The variations in soil density and penetration resistance declined as of the 12th day after tillage. This effect was considered a natural process of soil consolidation and influenced the temporal variation of soil CO2 emissions. Pore class distribution is an essential physical attribute to explain the temporal variations of soil CO2 emissions, and these classes are influenced by the applied management. Therefore, the study of these attributes must be taken into account when assessing the variation of CO2 emissions from agricultural soils.

Long‐term Soil Tillage and Cover Cropping Affected Arbuscular Mycorrhizal Fungi, Nutrient Concentrations, and Yield in Sunflower

Core Ideas Novel insights in the arbuscular mycorrhizal fungi tillage cover crop interaction based on a long term trial. Cover crops and soil tillage affect arbuscular mycorrhizal fungi colonization in the subsequent main crop. Nutrient concentrations and C/N ratio were affected by soil tillage. Reduction of soil tillage and whole‐year coverage are major factors for sustainable agriculture. Arbuscular mycorrhizal fungi (AMF) are major components of the native soil microbiome in agricultural soils. Soil tillage and cover cropping can play an important role in promoting AMF abundance. In the present study, the results of a field experiment comprising different soil tillage treatments (conventional, reduced, minimum, no‐tillage) in interaction with cover cropping (comprising AMF host and nonhost plants) in a common crop rotation with Triticum aestivum (winter wheat) and Helianthus annuus (sunflower) as the main crops are presented. Different cover crops (in mixtures or as single components) were cultivated in an existing soil tillage experiment established in 2009 in Austria. Soil tillage affected mycorrhization of winter wheat but not of cover crops. A different AMF root colonization were found in several cover crop species and in the subsequent sunflower. In this crop, AMF root colonization and spore density was further affected by soil tillage. The grain yields of the main crops were not altered by soil tillage. Significant interactions of soil tillage and cover cropping were found in the yield of sunflower and the C/N ratios. Furthermore, the nutrient concentrations of the plants were affected by soil tillage. This study shows that reduced soil tillage intensity combined with cover cropping enhances the abundance of AMF in the soil and affects the yield of the following main crop. Notably, mycorrhizal nonhost plants as cover crops do not lead to negative conditions for AMF in a common crop rotation.

Effects of conventional and reduced tillage methods on some traits of wheat in cotton-wheat system

Tillage is one of the&#x0D; most important agronomical practices especially for plant height (PH), grain&#x0D; yield (GY) and yield components in wheat production. This study was carried out&#x0D; in 2007–08 and 2008–09 growing seasons in&#x0D; Kahramanmaras, Turkey, to investigate&#x0D; response of five wheat cultivars (Adana, Ceyhan, Dogankent, Menemen and&#x0D; Yuregir) to conventional (CT) and reduced tillage (RT) systems after cotton&#x0D; harvest for PH, number of fertile&#x0D; spikes per m2 (SM), spike length (SL), number of fertile spikelets&#x0D; spike–1 (SS), number of grains spike–1&#x0D; (GS), 1000–kernel&#x0D; weight (KW) and GY components.&#x0D; The soil was ploughed at a depth of 25–30 cm in CT system, while it was not&#x0D; used in RT. The results indicated that all traits had greater values in 2008–09 than in 2007–08 except KW and GY. The tillage&#x0D; systems significantly affected&#x0D; PH, SM, SL, SS, GS and GY&#x0D; except KW. Over the two years,&#x0D; values of all traits in CT were higher than those of&amp;nbsp; RT. There&#x0D; was a significant and positive correlation for GY, SS, GS and KW between CT and&#x0D; RT. The cultivars were affected by year and tillage system. Dogankent&#x0D; cultivar had better performance and stable for most of the traits compared to&#x0D; others under CT and RT in both years.&amp;nbsp;

Effect of tillage systems on pea crop infestation with weeds

ABSTRACTIn a multi-year experiment, weed infestation of pea crop in three tillage systems was analyzed: a) conventional tillage (CT), b) reduced tillage (RT), and c) no-tillage (NT), and in two terms: 1) at 2–3 pea leaves stage (23–25 stage in BBCH scale) and 2) at the flat pod stage (75–79 BBCH). Treatments conducted in the CT system included shallow ploughing and pre-winter ploughing in the autumn. In the RT system, both these treatments were replaced by double cultivation, whereas only glyphosate treatment was applied in the NT system. In both terms of weed infestation assessment, the highest number and air-dry weight of weeds were determined in the RT system, lower ones in CT and the lowest ones in the NT system. In the first term, the number of weeds m−2 in the RT system was higher by 43.9% than in NT and by 26% than in CT system. Also in the second term was the weed number m−2 in RT higher by 58.6% than in NT and by 27.9% than in CT. Tillage systems differentiated also weed mass in pea crop. In RT, it was 4-fold higher than in NT and over 2-fold higher than in CT.

Changes in Soil Properties and Productivity under Different Tillage Practices and Wheat Genotypes: A Short-Term Study in Iran

Natural resources are the most limiting factors for sustainable agriculture in Iran. Traditional practices are intensive tillage that leads to a negative impact on crop productivity and soil properties. Conservation agriculture including tillage reductions, better agronomy, and improved varieties, showed encouraging results. The goal of this study was to test combined effect of tillage practices and wheat (Triticum aestivum L.) genotypes on soil properties as well as crop and water productivity. The experiment was conducted at Zarghan, Fars, Iran during 2014–2016. Experimental treatments were three-tillage practices—conventional tillage (CT), reduced tillage (RT), and no tillage (NT)—and four wheat genotypes were randomized in the main and subplots, respectively using split-plot randomized complete block design with three replications. Results showed NT had higher soil bulk density at surface soil, thereby lower cumulative water infiltration. The lowest soil organic carbon and total nitrogen were obtained under CT that led to the highest C:N ratio. Reduced tillage produced higher wheat yield and maize (Zea mays L.) biomass. Maximum irrigation water was applied under CT, which leads lower water productivity. The findings are based on short-term results, but it is important to evaluate medium- and long-term effects on soil properties, crop yields and water use in future.

Effect of contrasting tillage and cropping systems on soil aggregation, carbon pools and aggregate‐associated carbon in rainfed Vertisols

SummaryWorldwide, conservation agriculture practices involving minimal soil disturbances and retention of crop residue (&gt;30%) have been practised increasingly and recognized to enhance soil health by optimizing key soil attributes. However, little information is available on the short‐term effects of conservation agriculture practices on soil properties under rainfed Vertisols of Central India. Thus, our aim was to study the short‐term effects of contrasting tillage treatments and cropping systems on soil aggregation, aggregate‐associated carbon (C), carbon pools and crop productivity. This study comprised three tillage systems (TS), reduced tillage (RT), no tillage (NT) with retention of crop residue and conventional tillage (CT), together with four cropping systems (CS), namely soya bean (Glycine max L.) + pigeon pea (Cajanus cajan L.) (2:1), soya bean–wheat (Titricum durum L.), maize (Zea mays L.) + pigeon pea (1:1), and maize–chickpea Cicer arietinum L.). The experiment was laid out in a split‐plot design with three replicates. Soil samples were collected at four depths: 0–5, 5–15, 15–30 and 30–45 cm from the experimental field after completion of four crop cycles. Results indicated that at depths 0–5 and 5–15 cm, tillage and cropping system had a significant effect on aggregate mean weight diameter (MWD). The MWDs of 0.97 and 0.94 mm were larger for NT than CT (0.77 and 0.83 mm) at 0–5‐ and 5–15‐cm depths, respectively. Water‐stable aggregates (WSAs) were also larger for NT (70.74%) and RT (70.09%) than CT (59.50%) at 0–5 cm. Tillage practice, cropping system and their interaction had a greater effect (P &lt; 0.05) on the content of aggregate‐associated C for large macroaggregates (LM). There was more aggregate‐associated C for NT and RT at 0–5‐cm depth than for CT. Cropping system also had a significant effect (P &lt; 0.05) on aggregate‐associated C at 0–5‐cm depth. Soil organic C (%) fractions were in the order of non‐labile &gt;very labile &gt;less labile &gt;labile for 0–5‐ and 5–15‐cm depths after four crop cycles. Less labile and non‐labile C fractions contributed &gt;50% of TOC, indicating a more recalcitrant form of carbon present in the soil. Tillage had no significant effect (P &gt; 0.05) on crop yields after four crop cycles. Conservation agriculture can have a positive effect on aggregate stability, aggregate‐associated C and different carbon pools in a Vertisol.Highlights Does conservation agriculture affect soil aggregation, aggregate stability and carbon pools more than conventional tillage? The SOC concentration increases with aggregate size and provides physical protection and stabilization of carbon (C). Aggregate‐associated C content was significantly affected by tillage practices and cropping system. Less labile and non‐labile C fractions contribute &gt;50% TOC in the rainfed Vertisols of central India.