• Authors:
    • Haghighi, B. J.
    • Miri, H. R.
    • Ebrahimi, S. M.
  • Source: Advances in Environmental Biology
  • Volume: 6
  • Issue: 4
  • Year: 2012
  • Summary: The purpose of this study was evaluating the growth and compare yield and water consumption of corn under treatments of conventional tillage, reduced tillage and no tillage during the different irrigation intervals. This study was conducted at Arsanjan city, southern Iran in 2009. The experiment was split plot in randomized completely blocks design with three tillage methods (conventional tillage without residues, minimum tillage and conservation residues, and no tillage and reserve residues) as main factor and irrigation intervals (8 days, 11 days and 14 days intervals) as sub factor with four replication. Result of this study showed that 8 days irrigation interval and conventional tillage produced the highest grain yield, biological yield, ear number, seed number and seed weight in comparison with other treatments. But, by increasing irrigation interval to 14 days and decreasing water usage, no tillage and reserve residue treatment could prevent reduction in grain yield. In general results showed that residues management by reserving residue as a surface cover and improves tillage method to minimum and no tillage can increase corn yield through improvement soil organic carbon which is the main goal in conservation agriculture. We can reach to economic corn yield by reducing irrigation times and saving water usage in warm and dry regions, so it is possible to plant corn in this area directly in residue of previous crop.
  • Authors:
    • Carbonell-Bojollo, R.
    • Ordóñez-Fernández, R.
    • Veroz-González, O.
    • González-Sáncheza, E. J.
    • Gil-Ribes, J. A.
  • Source: Soil & Tillage Research
  • Volume: 122
  • Year: 2012
  • Summary: Conservation agriculture (CA) helps to mitigate climate change. Firstly, the modifications introduced by CA on the carbon dynamics in the soil directly result in an increase of the carbon (C) in the soil fraction. Secondly, CA drastically reduces C oxidation processes by diminishing the mechanical manipulation of the soil. Spain's position in relation to the Kyoto Protocol must be improved, as is one of the European countries in a non-compliance situation. With the aim of providing knowledge about the potential of CA as C sink in Spain, 29 articles on this subject were reviewed. According to 2010 CA uptake, the results demonstrated that conservation practices have the potential to promote the fixation in soil of about 2 Gg year(-1) more C than traditional tillage (TT) systems. As indicated by Tebrugge (2001), 3.7 Mg of CO2 are generated from 1 Mg of C through microbial oxidation processes taking place in the ground, meaning that through CA almost 7.5 Gg of CO2 could be sequestered from the atmosphere every year until the equilibrium is reached. C fixation was found to be irregular over time. C fixation rates were high in newly implemented systems during the first 10 years, reaching top values of 0.85 Mg ha(-1) year(-1) for no-tillage (NT) and 1.54 Mg ha(-1) year(-1) for cover crops (CC) implemented in-between perennial tree rows. After those first 10 years, it followed a period of lower but steady growth until equilibrium was reached. Nevertheless, C decreases of 0.16 Mg ha(-1) year(-1) in the first 10 years may be expected when practicing minimum tillage (MT). C sequestration rate resulted higher in case farmers do crop rotations in NT and MT rather than monoculture. In woody crops, studies reported higher C fixation values for native species when compared to sowed CC. Also, climate conditions seem to affect C sequestration rate in Spain. Although in NT differences observed between maritime and continental climates are not pronounced, as approximately 25% of the values recorded in both climates are equal, in the case of MT about 75% of maritime climate values result higher than the continental situation. (c) 2012 Elsevier B.V. All rights reserved.
  • Authors:
    • de Ridder, N.
    • Vanlauwe, B.
    • Pypers, P.
    • Guto, S. N.
    • Giller, K. E.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 1
  • Year: 2012
  • Summary: Soil fertility gradients develop on smallholder farms due to preferential allocation of inputs. A multi-location on-farm trial was conducted in Meru South, Central Kenya whose overall aim was to test minimum tillage and crop-residue retention practices in socio-ecological niches across heterogeneous smallholder farms. We identified three soil fertility classes together with the farmers, namely: good, medium, and poor. In each soil fertility class, two tillage (minimum or regular) and two crop residue (removed or retained) practices were tested for four consecutive seasons. Maize (Zea mays L.) grain yields in the good fields were above 2.5 Mg ha(-1) across cropping seasons and cumulated yields were not influenced by tillage or crop residue management. The grain yields in the medium fields ranged between 1.3 and 5.4 Mg ha(-1) and were greater with crop residue retention. In the poor fields, grain yield was
  • Authors:
    • Soomro, B. A.
    • Markhand, G. S.
    • Soomro, M. H.
  • Source: Pakistan Journal of Botany
  • Volume: 44
  • Issue: 1
  • Year: 2012
  • Summary: The drought is one of the biggest abiotic stresses for crop production in arid and semi-arid agriculture. Thus it is a challenge for plant scientists to screen and develop the drought tolerant cotton lines. In this study, 31 cotton genotypes/cultivars were evaluated under two irrigation regimes i.e., seven irrigations (Control) and two irrigations (Stress), using split plot design with four replications. The crop growth, yield and some physiological parameters were studied. There were high inter-varietal differences for all the parameters under control as well as drought stress. Although all the varieties for all parameters were significantly affected by drought but however, CRIS-9, MARVI, CRIS-134, CRIS-126, CRIS-337, CRIS-355 and CRIS-377 maintained highest performance for all the parameters studied under high drought conditions.
  • Authors:
    • Fora, G. C.
    • Solomonesc, A.
    • Moatar, M.
    • Chisalita, I.
    • Stefan, C.
    • Olaru, D.
  • Source: Journal of Horticulture, Forestry and Biotechnology
  • Volume: 16
  • Issue: 2
  • Year: 2012
  • Summary: From planting to emergence, the range is over 30 days (the potato 18-25 days). During this period must be destroyed weeds and crust can form especially on heavy land and wet weather. The best results are obtained when the works are done as soon as weeds appear. The first work is performed at 10-14 days after planting. When planting was done on rising land, harrow ground working-net, the aggregate of three fields, the working width of 8.4 m and a forward speed of 5.7 km/h, harrows destroy the weeds and crust rising land ridge, and the interval between rising land. After 1-4 days working again, this time with thinning type cultivator equipped with tracks. To destroy weeds and crust in the area of rising land and by restoring them, cover and choke the weeds that tend to rise. Successive work-net harrow and cultivator parts such rarity, recovery Billon, repeats again (when they planted tuber sprouting) or 2 times to other cultures, after intervals of 8-12 days.
  • Authors:
    • Vazin, F.
    • Abbasi, M.
  • Source: Advances in Environmental Biology
  • Volume: 6
  • Issue: 4
  • Year: 2012
  • Summary: In most areas of Isfahan Province, the maize is cultivated as a second crop after harvesting the wheat or barely and the farmers of this region are confronting with time-limit problems in performing correct yield of providing the soil bed, and the tillage is an expensive and energy-consuming yield. Thus, for examining the effect of tillage on the elimination of mechanical yield and saving the time and the expense of performing yield as well as the effect of appropriate date for planting the maize on the performance and its components, an experiment is conducted as a split plot design, 4 times in the agricultural year 2010 in Mourchekhort area of Isfahan. The factors including tillage in two levels (Current Tillage "CT" and Non-tillage "NT") on the main plot and the planting date in three levels (29 th June-15 th July-28 th July) with 15-day interval on the secondary plot were operated on the maize sort No. I704. The tillage system is not significantly effective on the biological performance. In tillage system, the performance of the grain, the number of corns in the maize row and the total number of corn in the maize showed respectively 10%, 12% and 22% increases, compared to those in nontillage system. On 29 th June, the weight of one-thousand corns was decreased 13% and the performance of the corn, the number of corns in the maize row and the total number of corns in the maize was respectively increased in 35%, 16% and 30% compared to those on 29 th July. Reciprocal effect of tillage system and planting dates didn't effect on the corn's performance and its components. Considering the results achieved, the best planting date for both tillage systems in this area is 29 th June.
  • Authors:
    • Coquet, Y.
    • Justes, E.
    • Benoit, P.
    • Alletto, L.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 153
  • Year: 2012
  • Summary: Water drainage and herbicide degradation and leaching were studied during four years in a continuous maize field managed with two tillage systems and two types of fallow periods. The tillage systems consisted of either a conventional practice with mouldboard ploughing (28 cm-depth) or a conservation practice with superficial tillage (
  • Authors:
    • Armentano, G.
  • Source: L'Informatore Agrario
  • Volume: 68
  • Issue: 1
  • Year: 2012
  • Authors:
    • Dercon, G.
    • Kumar S.
    • Garg, A. K.
    • Manchanda, J. S.
    • Aulakh, M. S.
    • Nguyen, M. L.
  • Source: Soil & Tillage Research
  • Volume: 120
  • Year: 2012
  • Summary: Continuing cereal-based crop rotations such as rice-wheat, intensive cultivation and complete removal of postharvest crop residue (CR) for animal consumption and fuel, or its burning have reduced the organic matter content and productivity of irrigated semi-arid subtropical soils of South Asia. Identification of effective strategies for the management of tillage and CR could foster sustainable and environmentally sound agricultural systems. To this effect, a 4-year field experiment was established with annual soybean-wheat rotation under subtropical climate conditions in the Indo-Gangetic Plains of Northwestern India to evaluate the integrated effects of tillage, CR retainment, mineral fertilizers and farmyard manure (FYM) on crop production, nutrients uptake, soil moisture storage and temperature dynamics. The experimental soil was loamy sand, poor in organic C and low in available P. Sixteen treatment combinations involved recommended and 25% higher NP rates without or with 10 t FYM ha -1 and CR incorporated in conventional tillage (CT) and retained on the soil surface in conservation agriculture (CA) system. The results clearly revealed that (a) soybean yield was 2-6% higher in CA than CT in different treatments with and without CR, (b) significantly higher uptake of N and P by soybean from CR-amended treatments of both CT and CA, which reflected its effect in improving the soybean yield, (c) the current fertilizer NP recommendation of 20 kg N and 26 kg P ha -1 for soybean is not adequate and either application of 25% higher NP rate (25 kg N and 33 kg P ha -1) or additional 10 t FYM ha -1 is required for optimum crop production of ~2500 kg ha -1, (d) CA conserved more water in soil profile than CT, however, the differences in soil moisture storage in CT vis-a-vis CA were not reflected in soybean yield presumably due to frequent wetting of soil by heavy monsoonal rains, (e) the wheat yield was highest in both CT and CA systems when grown with the application of 150 kg N and 33 kg P ha -1 without CR and was 7% higher in CA (4140 kg ha -1) than CT (4048 kg ha -1), and (f) retention of CR on soil surface in winter-grown wheat under CA reduced wheat yield by 8-24% and N uptake by 3-5% as a consequence of mulching effects creating cooler environment in surface soil layer during initial 3 weeks after seeding, which led to the delayed germination and relatively poor crop growth during initial period.
  • Authors:
    • Hensley, M.
    • Bennie, A. T. P.
    • Botha, J. J.
    • Rensburg, L. D. van
  • Source: Water SA
  • Volume: 37
  • Issue: 5
  • Year: 2011
  • Summary: This review provides an overview of Water Research Commission (WRC)-funded research over the past 36 years. A total of 28 WRC reports have been consulted, 13 of these compiled by the University of the Free State, 4 by the University of Fort Hare, and the remainder mainly by the ARC-Institute for Soil Climate and Water. This work has resulted in extensive capacity building in this field - numerous technical assistants and 58 researchers have been involved, of which 23 are still active in research. The focus on the water flow processes in the soil-plant-atmosphere continuum (SPAC), with particular emphasis on processes in the soil, has greatly enhanced understanding of the system, thereby enabling the formulation of a quantitative model relating the water supply from a layered soil profile to water demand; the formulation of logical quantitative definitions for crop-ecotope specific upper and lower limits of available water; the identification of the harmful rootzone development effects of compacted layers in fine sandy soils caused by cultivation, and amelioration procedures to prevent these effects; and management strategies to combat excessive water losses by deep drainage. The explanation of the way in which SPAC is expressed in the landscape in the form of the ecotope has been beneficial with regard to the extrapolation of studies on particular SPACs to the large number of ecotopes where detailed studies have not been possible. Valuable results are reported regarding rainfall and runoff management strategies. Longer fallow periods and deficit irrigation on certain crop ecotopes improved rainfall use efficiency. On semi-arid ecotopes with high-drought-risk clay and duplex soils and high runoff losses, in-field rainwater harvesting (IRWH), designed specifically for subsistence farmers, resulted in maize and sunflower yield increases of between 30% and 50% compared to yields obtained with conventional tillage. An indication of the level of understanding of the relevant processes that has been achieved is demonstrated by their quantitative description in mathematical and empirical models: BEWAB for irrigation, SWAMP mainly for dryland cropping, and CYP-SA for IRWH. Five important related research and development needs are identified. The WRC has played, and continues to play, an important role in commissioning and funding research on water utilisation in agriculture and has clearly made an excellent contribution to the progress made in addressing the needs and requirements of subsistence, emergent and dryland farmers in South Africa.