Total, particulate organic matter and structural stability of a Calcixeroll soil under different wheat rotations and tillage systems in a semiarid area of Morocco (original) (raw)
Related papers
2001
Wheat production in Morocco is constrained by both scarce climate and degraded soil quality. There is an urgent need to revert production decline while restoring country's soils. Among conservation tillage systems known for their improvement in yield, no-till technology was found to in¯uence soil quality as well. Soil quality indices are also affected by wheat rotations at medium and long-terms. This paper discusses changes in selected properties of a Calcixeroll soil, including total and particulate soil organic matter (SOM), pH, total N and aggregation, subjected, for 11 consecutive years, to various conservation and conventional agricultural systems. Tillage systems included no-tillage (NT) and conventional tillage (CT). Crop rotations were continuous wheat, fallow±wheat, fallow±wheat±corn, fallow±wheat±forage and fallow±wheat±lentils. Higher aggregation, carbon sequestration, pH decline and particulate organic matter (POM) buildup are major changes associated with shift fro...
Agronomie, 2002
This paper discusses changes in selected properties of a Calcixeroll soil, including total and particulate soil organic matter, pH, total N and aggregation, subjected for 11 consecutive years to various conservation and conventional agricultural systems. Tillage systems included no-tillage (NT) and conventional tillage (CT); crop rotations were Continuous Wheat; Fallow-Wheat, Fallow-Wheat-Corn, Fallow-Wheat-Forage and Fallow-Wheat-Lentils. Higher aggregation, organic matter contents, pH and particulate organic matter (POM) build-up are major changes associated with a shift from a conventional-to a no-tillage system. The fallow system resulted in a reduction of soil organic matter (SOM) content, but 3-year wheat rotations including fallow tended to improve soil quality attributes more than 2-year wheat rotations. Another important finding is the accumulation of SOM (in terms of carbon and nitrogen) in the NT surface horizon (0-2.5 cm) without depletion at the deeper horizon (2.5-20 cm) compared to the tilled treatments. There was an increase in SOM in the topsoil (0-20 cm) over the 11-yr study period under NT, while CT did not affect this soil quality indicator much. Benefits from crop rotation in terms of organic matter varied, with fallow-wheat-forage exhibiting the maximum value. Better stability of aggregates was demonstrated by a significantly greater aggregation index (mean weight diameter) value under NT (3.8 mm) than under the CT system (3.2 mm) at the soil surface. Hence, combined use of no-tillage and 3-yr rotation helped to improve soil quality in this experiment. no-tillage / soil quality / soil organic matter / structural stability Communicated by Mohamed Helal (Braunschweig, Germany)
Effects of long-term tillage practices on the quality of soil under winter wheat
Plant, Soil and Environment
These studies were done in 2013–2016 on the effects of two tillage systems on the quality of a loamy sand soil (Eutric Fluvisol) and were based on a field experiment started in 2002. Winter wheat was grown in conventional tillage (CT) with mouldboard ploughing (inversion) tillage; and reduced (non-inversion) tillage (RT) based on soil crushing-loosening equipment and a rigid-tine cultivator. Chopped wheat straw was used as mulch in both treatments. The physical, chemical and biological properties of the soil were investigated. RT increased soil bulk density in the 0–5 cm and 5–10 cm depth layers in comparison with CT. The greatest content of soil organic carbon (SOC) was found in the 0–5 cm layer under RT. The BIOLOG EcoPlate System showed that soil under RT had a greater metabolic activity and diversity of microbial communities than soil under CT. RT improved the quality of the surface soil as shown by the greater content of SOC and microbial activity measured in terms of dehydroge...
Soil Organic Carbon and Nitrogen Fractions under Different Land Uses and Tillage Practices
Communications in Soil Science and Plant Analysis, 2016
A long-term field experiment was conducted to design and implement alternative production systems with increased resource use efficiency, productivity and to determine the effect of tillage systems and mineral fertilizers on soil organic carbon patterns. This experiment intended to evaluate the effects of these management strategies on soil structural formation and structural stabilization of a sandy loam soil. The shift from puddled-transplanted rice on the flat land to raised bed systems affects the productivity and resource use efficiency of the rice-wheat system. Therefore, the potential benefits and constraints of tillage crop residue practices need to be quantified on short to long-term basis, optimum layouts and management systems to maximize yield and efficiency. Due to lesser energy input and higher output T3 ZT with 6tha-1 residue retained had 20% and 5% higher energy use efficiency than T7 CT and T6 PRB with 6tha-1 residue retained. Undisturbed soil samples were collected from the 15 to 100 cm soil layer in the field grown with wheat to assess SOC, bulk density, C restoration rate, C sequestered, C sequestration efficiency (%) and crop yield. However, at the end of the 18 years period, SOC was 25% greater with T6 than T7, 16% greater with T4 than T1, and 17% higher with T2 than T7. Average SOC concentration of the control treatment was 0.54%, which increased to 0.65% in the RDF treatment and 0.82% in the RDF+FYM treatment and increased enzyme activities, which potentially influence soil nutrients dynamics under field condition. Compared to F1 control treatment the RDF+FYM treatment sequestered 0.28 Mg C ha-1 yr-1 whereas the NPK treatment sequestered 0.13 Mg C ha-1 yr-1. As tillage intensity increased there was a redistribution of SOC in the profile, but it occurred only between ZT and PRB since under CT, SOC stock decreased even below the plow layer. Increased SOC stock in the surface 50 kg m-2 under ZT and PRB was compensated by greater SOC stocks in the 50-200 and 200-400 kg m-2 interval under residue retained, but SOC stocks under CT were consistently lower in the surface 400 kg m-2. Over the last 18 years, CT lost 0.83 ±0.2 kg of C m-2 while ZT gain 1.98 ±0.3 and PRB gain 0.97 ±0.2 kg of C m-2 in the 1200 kg of soil m-2 profile. These findings suggest that carbon sequestration can be improved if treatments T4 or T6 are used in lieu of T7, respectively.
Soil and Tillage Research, 2010
Soil organic carbon (SOC) is one of the principal indicators of soil quality. Its size fractions have been proposed as high sensitivity indicators in order to detect changes generated by different soil use and management intensities. The objective was to compare the impact of different soil management practices after 10 years on SOC distribution and its size fractions. Treatments consisted in two rotation systems (rotations of continuous annual crops and rotations of 3 years of crops and 3 years of pastures), performed with conventional tillage (CT) and no-till (NT). In 2000, NT treatments were additionally split into C 3 or C 4 summer crops. In 2003, soil was sampled at 0-3, 3-6, 6-12, 12-18, 18-40, 40-60 and 60-80 cm depths and SOC was determined. At the first four depths, SOC associated with particulate organic matter (POM-C) and with the soil mineral fraction (MAOM-C) were determined. Changes in carbon indicators (SOC and its size fractions) occurred mainly in the first 3 cm of soil, and with the exception of POM-C, were diluted when considering the 0-18 cm depth. Inclusion of pastures in the rotation was a better alternative to continuous cropping in CT systems, since it had better C indicator values. However, NT improved indicator values compared with LC, especially when C 4 species were included in the rotation; no differences were found between continuous cropping or crop-pasture rotations. These results allowed discriminate different combinations of crops and tillage systems that contribute to maintain or increase SOC, suggesting a sustainable management of the soil resource.
Ecological Engineering & Environmental Technology, 2022
Sustainable management of agricultural practices can improve soil organic status, soil quality (SQ), and yields. The study was conducted to test the impact of tillage (conventional (CT) and no-till (NT)), residues (vetch (C1) and uncover soil (C0)), and three nitrogen (N) fertilization rates (30, 60, and 90 N kg ha -1) on soil organic carbon (SOC), total nitrogen (N), C/N ratio, soft wheat yields and SQ. The experiment was established in 2010 in the Moroccan semi-arid. After ten years, the SOC concentration was greater under NT (9.4 g/kg) compared to CT (8.4 g/kg). Crop residues also enhanced SOC (10 g/kg) contrary to C0 (8.1 g/kg). Application of N fertilization showed profound effects on total N, increasing levels of N fertilization led to higher total N irrespective of tillage. Crop residues increased total N (0.6 g/kg) better than C0 plots at the horizon 20–40 cm. Soft wheat revealed an improvement under NT (4213.8 kg ha-1) versus CT (3785.6 kg ha-1) and it responded positively ...
Soil & Tillage Research, 2002
Under semiarid Mediterranean climatic conditions, soils typically have low organic matter content and weak structure resulting in low infiltration rates. Aggregate stability is a quality indicator directly related to soil organic matter, which can be redistributed within soil by tillage. Long-term effects (1983Long-term effects ( -1996 of tillage systems on water stability of pre-wetted and air dried aggregates, soil organic carbon (SOC) stratification and crop production were studied in a Vertic Luvisol with a loam texture. Tillage treatments included conventional tillage (CT), minimum tillage (MT) and zero tillage (ZT) under winter wheat (Triticum aestivum L.) and vetch (Vicia sativa L.) rotation (W-V), and under continuous monoculture of winter wheat or winter barley (Hordeum vulgare L.) (CM). Aggregate stability of soil at a depth of 0-5 cm was much greater when 1-2 mm aggregates were vacuum wetted prior to sieving (83%) than when slaked (6%). However, slaking resulted in tillage effects that were consistent with changes in SOC. Aggregate stability of slaked aggregates was greater under ZT than under CT or MT in both crop rotations (i.e., 11% vs. 3%, respectively).
Impact of changing crop rotation to continuous wheat on soil characteristics in semiarid areas
To evaluate the effect of crop rotation on soil structural properties and aggregate fractal dimension, three locations were selected in Maragheh and Hashtroud areas, northwest of Iran. Four crop rotations were implemented and several soil physical and chemical properties were evaluated. In wheat-chickpea and wheat-fallow rotation treatments (T2 and T4) average bulk density (BD) of 1.155 g cm -3 was significantly (P< 0.01) lower than continuous wheat cropping (T1) and wheat-fallow-wheat-wheat-wheat (T3) treatments with BD of 1.29 g cm -3 . Water aggregate stability (WAS) in T4 became significantly (P<0.01) greater than other rotations. Saturated water content (θ s ) of T1 and T3 (0.39 cm 3 cm -3 ) was significantly (P< 0.01) lower than T2 and T4 (nearly equal to 0.55 cm 3 cm -3 ). The lowest saturated hydraulic conductivity (K S ) of about 2.0 cm h -1 occurred in T1 and T3, and the highest (5.27 cm h -1 ) in T4. Soil moisture content (θ m ) in T2 and T4 during GS21 growth stage significantly exceeded those of T1 and T3. Biological yields in T2 and T4 were nearly equal (3.05 t ha -1 ) and were significantly (P< 0.05) greater than T1 and T3 (1.5 t ha -1
Changes in some soil properties in a Vertic Argiudoll under short-term conservation tillage
Soil and Tillage Research, 2001
The purpose of this work was to determine whether some soil physical and chemical properties, and microbial activity were affected by two conservation tillage systems in a Chernozemic clay loam soil (Vertic Argiudoll), after 5 years of trial initiation. Two crop sequences, corn (Zea mays L.)-wheat (Triticum aestivum L.)/soybean (Glycine max (L.) Merr.) and wheat/ soybean, under chisel plowing (ChP) and no till (NT) were evaluated. Physical and chemical properties were also analyzed taking the same soil without disturbance as reference. The Hénin instability index (HI) was larger in ChP than in NT in both corn-wheat/soybean (C-W/S) and wheat/soybean (W/S) sequences ðP 0:05Þ. The C-W/S sequence differed from W/S ðP 0:01Þ in total organic carbon (TOC). As regards organic carbon fractions, no differences were found in labile organic carbon (LOC), while W/S under ChP showed the lowest value ðP 0:01Þ of humified organic carbon (HOC). No differences were found in microbial respiration either in crop sequences or in tillage systems. Soil physical and chemical properties differentiated crop sequences and tillage treatments from the undisturbed soil when a Student's t-test was performed. Five years elapsed since the beginning of this trial was time enough to detect changes in some of the soil properties as a consequence of management practices. An important reduction in the soil structural stability was observed as related to the undisturbed soil. However, the C-W/S sequence under NT resulted in lower soil degradation with respect to the other treatments.