• Authors:
    • Cociu, A. I.
  • Source: Romanian Agricultural Research
  • Issue: 28
  • Year: 2011
  • Summary: This research was aimed to identify the most suitable tillage systems for sustainable winter wheat ( Triticum aestivum L.) yield levels, with best economic efficiency, assuring at the same time high quality soil physical and mechanical properties. The field experiments were carried out at Fundulea on a cambic chernozem soil type. Four tillage systems were tested to determine their influence on soil water content, soil macro-aggregates, resistance to soil penetration, wheat grain yield and its components, and crop economic efficiency. The following tillage systems were studied: traditional, with moldboard plough (TS); chisel plough tillage - primary tillage executed with chisel implement type without furrow over throwing (CS); disc/sweep tillage, providing a combined effect of vegetal remnants chopped with disc implements along with soil work with arrow type tools, without furrow over throwing (DS); No till (NT) - without any tillage work. In comparison with TS variant, soil conservation tillage systems (SCTS), as CS, DS and NT, increased the soil water content, recorded at seeding time, with 0.8%, 3.9%, and 4.1%, respectively. Soil water content, recorded at harvest time for CS and NT variants was 1.3% and 2.5% higher than in the case of TS (P2 mm with 5.5%, and the mean weighted diameter of soil particles resulted by dry sieving, with 5.5% and 10%, respectively. Yield components recorded for soil conservation tillage systems (CS, DS, and NT) did not differ significantly from those evaluated for traditional system (TS), but the superior values of 1000 kernels weight and spike density suggest that these components contributed more to higher yields, obtained with SCTS, than grain weight per spike, number of grain per spike, and number of grains per square meter. With regards to economic efficiency, the outputs of all tested SCTS were significantly greater than the TS. The present study, revealing important advantages of soil conservation tillage systems over the traditional one, revealing the improvement of soil physical and mechanical properties, higher winter wheat yield levels and higher crop economic efficiency, invites farmers from South Plain of Romania to adopt soon these new progressive systems.
  • Authors:
    • Alionte,E.
    • Cociu,A. I.
  • Source: Romanian Agricultural Research
  • Issue: 28
  • Year: 2011
  • Summary: Previous research revealed that winter wheat ( Triticum aestivum L.), maize ( Zea mays L.), and soybean [ Glicine max (L.) Merill] respond more or less to the soil deep loosening work and different tillage systems, depending on the environment. The few data available showed that these agricultural practices also have a certain influence on nutritive values and physical properties of the harvested products. A three year (2008-2010) winter wheat, maize and soybean field experiment was carried out at Fundulea, Romania, on a cambic chernozem type, with the objective of evaluating the influence of different conservative tillage systems (chisel till, disc till, strip till and no till), with and without deep soil loosening, on yield and some important quality parameters. This research revealed that for winter wheat, the tillage systems and climatic conditions which favored grain yield were unfavorable for protein content. Deep soil loosening and tillage systems had a similar influence on protein and grain yields. 1000 kernels weight and test weight were not influenced significantly by the deep soil loosening and tillage systems. For maize, the application of no till resulted in a significant grain yield increase. Conservation tillage systems may influence negatively grain protein content, depending on the climatic conditions. Protein, fat and starch yields were significantly influenced by tillage systems, year and their interaction. These influences were caused mainly by the magnitude of grain yields differences. 1000 kernels weight and test weight were not significantly influenced by the deep soil loosening and tillage system. For soybean, climatic conditions and tillage systems which influenced the grain yield, affected in a similar way the protein and fat contents. Deep soil loosening had a significant influence only on the grain yield and protein content. Deep soil loosening, tillage system and climatic conditions which influenced the grain yield affected similarly the protein yield. In the case of fat yield, these effects are more or less the same only for deep soil loosening and years, but not for tillage systems.
  • Authors:
    • Allen, D. E.
    • Reeves, S.
    • Menzies, N. W.
    • Dalal, R. C.
    • Wang, W.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 6
  • Year: 2011
  • Summary: Land-use change from perennial grasslands to cultivated croplands leads to reduced soil organic C (SOC) and total N. Among other factors, introduction of annual crops and soil disturbance by tillage may account for reduced amounts of SOC and total N. However, agricultural practices of no-till and N fertilizer application may maintain soil N in cropped soils. We measured soil N changes and N-use efficiency in a field experiment initiated in 1968, consisting of completely randomized tillage practices (conventional mechanical till [CT], and no-till [NT]), crop residue management (residue burned [RB], and residue retained [RR]), and N fertilization (0, 30, and 90 kg N ha -1) on a Vertisol (Ustic Pellusert) over 40 yr. Crops grown were mainly wheat ( Triticum aestivum L.) except for five barley ( Hordeum vulgare L.) crops early in the experiment. Significant effects of treatments on soil total N were primarily confined to the top 0.1-m depth. Soil total N exponentially declined in all treatments even though apparent fertilizer N recoveries during this period (1969-2008) were only 46 and 59% of N applied at 90 and 30 kg N ha -1, respectively. Mineral N in the soil profile (0-1.2 m) ranged from 68 to 496 kg N ha -1. Nitrogen-use efficiency was similar ( P=0.13) under CT and NT in this Vertisol. However, crop residue retention and a low rate of N application had greater N-use efficiency (35-40%) than RB and a high rate of N application (21-25%) under the annual cereal grain cropping system. If perennial grasslands are considered ecological benchmarks for agricultural sustainability, primarily through large root biomass that utilizes water and nutrients efficiently, then the challenge remains to develop cropping systems that successfully mimic grassland ecosystems.
  • Authors:
    • de Campos, B. -H. C.
    • Carneiro Amado, T. J.
    • Bayer, C.
    • da Silveira Nicoloso, R.
    • Fiorin, J. E.
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 35
  • Issue: 3
  • Year: 2011
  • Summary: Soil organic matter (SOM) plays a crucial role in soil quality and can act as an atmospheric C-CO2 sink under conservationist management systems. This study aimed to evaluate the long-term effects (19 years) of tillage (CT-conventional tillage and NT-no tillage) and crop rotations (R0-monoculture system, R1-winter crop rotation, and R2- intensive crop rotation) on total, particulate and mineral-associated organic carbon (C) stocks of an originally degraded Red Oxisol in Cruz Alta, RS, Southern Brazil. The climate is humid subtropical Cfa 2a (Koppen classification), the mean annual precipitation 1,774 mm and mean annual temperature 19.2 degrees C. The plots were divided into four segments, of which each was sampled in the layers 0-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30 m. Sampling was performed manually by opening small trenches. The SOM pools were determined by physical fractionation. Soil C stocks had a linear relationship with annual crop C inputs, regardless of the tillage systems. Thus, soil disturbance had a minor effect on SOM turnover. In the 0-0.30 m layer, soil C sequestration ranged from 0 to 0.51 Mg ha(-1) yr(-1), using the CT R0 treatment as base-line; crop rotation systems had more influence on soil stock C than tillage systems. The mean C sequestration rate of the cropping systems was 0.13 Mg ha(-1) y(-1) higher in NT than CT. This result was associated to the higher C input by crops due to the improvement in soil quality under long-term no-tillage. The particulate C fraction was a sensitive indicator of soil management quality, while mineral-associated organic C was the main pool of atmospheric C fixed in this clayey Oxisol. The C retention in this stable SOM fraction accounts for 81 and 89% of total C sequestration in the treatments NT R1 and NT R2, respectively, in relation to the same cropping systems under CT. The highest C management index was observed in NT R2, confirming the capacity of this soil management practice to improve the soil C stock qualitatively in relation to CT R0. The results highlighted the diversification of crop rotation with cover crops as a crucial strategy for atmospheric C-CO2 sequestration and SOM quality improvement in highly weathered subtropical Oxisols.
  • Authors:
    • Devine, S.
    • Markewitz, D.
    • Hendrix, P.
    • Coleman, D.
  • Source: Forest Science
  • Volume: 57
  • Issue: 1
  • Year: 2011
  • Summary: Forest succession (FS) and no-till (NT) agriculture are generally assumed to have a beneficial effect on surficial soil organic C (SOC) stocks compared with conventional tillage (CT) management; however, land use effects to depths >30 cm remain uncertain. In this research we compared SOC contents and composition to 2 m under CT, NT, and FS at the 30-year Horseshoe Bend agroecosystem experiment in Athens, Georgia, USA. Soils from 0 to 2 m were fractionated into particulate organic C (POC) (53-2000 m) and fine C (<53 m) fractions, and bulk soil delta 13C signatures were determined. Soils from 0 to 28 cm were dry- and wet-sieved to estimate aggregate stability. Soil solutions were also collected at 0, 15, and 100 cm for dissolved organic C (DOC) analysis. Full-profile (0-2 m) SOC storage is 52 Mg ha -1 in CT, 60 Mg ha -1 in NT, and 62 Mg ha -1 in FS. Significant differences are limited to 0-5 cm and are linked to enhanced aggregate stability under NT and FS. Increases in subsoil POC under FS and changes in soil delta 13C and C/N ratio indicate that substantial subsoil C cycling has occurred. DOC fluxes at 0 cm were significantly greater under NT (200 kg ha -1 year -1) and FS (210 kg ha -1 year -1) than under CT (80 kg ha -1 year -1). DOC fluxes at 15 cm are estimated to be 20 kg ha -1 year -1 under CT and NT and 40 kg ha -1 year -1 under FS. At 100 cm, DOC fluxes are 2 kg ha -1 year -1, regardless of land use. An increase in FS POC of 2 Mg ha -1 from 15 to 100 cm outweighs cumulative differences in DOC input to this layer, implicating deep forest rooting and bioturbation as active mechanisms in subsoil C change. Whereas differences in SOC content were concentrated near the surface, dynamic changes in C cycling extend well below the plow layer.
  • Authors:
    • Dicu, D.
    • Ţărau, D.
    • Borza, I.
  • Source: Research Journal of Agricultural Science
  • Volume: 43
  • Issue: 3
  • Year: 2011
  • Summary: This study presents some aspects regarding the physical-geographical characterization necessary for the experimental field localization. Briefly introduced are the geology and lithology of surface materials, climate conditions, land drainage etc., as defining elements for edaphic resources' main characteristics. To determine the physical, chemical and biological properties of Cambic Chernozems from Aradul Nou (Romania), more samples were collected in both natural settlement and in disturbed settlement. Soil conditions also determined the defining characteristics for the ecosystems productivity, granulated structure and humus content. Maize, soyabean and wheat were used as test plants. The results obtained in the soil and climate conditions mentioned, although not allow for a clear formulation of recommendations in the culture systems tested, but the background information gathered is extremely valuable for scientific substantiation of appropriate technologies in the future for climatic conditions specific of the area in which investigations were undertaken as well as similar areas, conservative tillage systems representing alternatives to conventional tillage systems by the effects of conservation of soil properties and yields In terms of crop suitability to no-till system, soil texture has some restrictions due to clay-clay and secondary compaction, without excluding the possibility of adopting no-till practices. Yields obtained by applying the conservative systems, can achieve differentiated results that show, at least close if not superior to classical ones. Choosing the system should be made, as appropriate, depending on plant, soil and climate specific conditions. The research supports the ability to promote no-till technology in production established itself selective implementation, where conditions are suitable ecopedological this system of agriculture, under effective management.
  • Authors:
    • Dubie, T. R.
    • Greenwood, C. M.
    • Godsey, C.
    • Payton, M. E.
  • Source: Southwestern Entomologist
  • Volume: 36
  • Issue: 1
  • Year: 2011
  • Summary: A long-term tillage study plot was sampled to evaluate the effects of tillage on soil-dwelling microarthropods. Soil (300 cm 3) was sampled on four dates during two growing seasons from conventional and no-till plots of winter wheat. Microarthropods were extracted using Tullgren funnels and enumerated into seven taxonomic categories: (1) Total abundance, (2) Oribatida, (3) Mesostigmata, (4) Prostigmata, (5) Astigmata, (6) Collembola, and (7) other invertebrates. Abundance within six of the seven groups was greater in no-till than conventionally tilled soil on seven of the eight sampling dates: (1) Total abundance in conventional till 6.441.68 and 21.395.35 in no-till, (2) Oribatida in conventional till 1.060.36 and 7.332.23 in no till, and (3) Other invertebrates in conventional till 4.500.82 and 10.672.85 in no till. The Mesostigmata and Collembola showed significant differences between conventionally tilled and no-till plots on multiple dates. In contrast, mites in the group Prostigmata were more abundant in conventionally tilled soil (3.891.13 versus 2.000.88 in no till). Abundance of soil microarthropods in no-till plots generally increased (21.395.35 in Season 1 to 42.424.59 in Season 2), which might indicate gradual recovery of the habitat. Assessments of soil quality in no-till agricultural systems should include evaluations of beneficial soil fauna such as microarthropods.
  • Authors:
    • Duboc, O.
    • Zehetner, F.
    • Gerzabek, M. H.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 6
  • Year: 2011
  • Summary: The increase in crop production brought by the green revolution in India is now shadowed by new challenges related to soil degradation (e.g., erosion, decline of soil organic matter content, salinization) and scarcity of water resources. The present work particularly discusses the contribution of no-till and organic farming, which are increasingly being adopted in India, to meet the increasing food demand in a sustainable way. Under no-till, erosion is reduced to rates close to those found in natural ecosystems, provided enough mulch is retained at the surface which is usually not the case in India, because of competing uses, for example, fodder, fuel, construction material, and also crop residue burning for land preparation. No-till should therefore not be considered separately from complementary measures, aiming at retaining mulch on the soil surface. Efficient recycling of organic material needs to be implemented concomitantly with diversifying fodder and fuel sources which requires enhancing the multifunctionality of farming systems. These prerequisites make it difficult for farmers to adopt no-till, particularly the poorer ones for whom experimentation with new techniques often involve unbearable financial risks. Organic farming apprehends the farm as an organism, and is thus a good option to improve sustainability as introduced above, by e.g., closing nutrient cycling. However, organic farming typically implies tillage for weed control (no chemical herbicides). "Natural farming," as promoted by Fukuoka (197834. Fukuoka, M. 1978. The one-straw revolution: an introduction to natural farming, Rodale Press. View all references) combines no-till with organic farming. An overview of available literature on Indian experiences with "natural farming," most of it originating from unconventional sources (i.e., reports available on Internet, but no peer reviewed literature) indicates that crop yields can compare well with the highest yields in a particular region. Increased productivity and environmental benefits are also often mentioned. The limited accuracy of these sources makes it necessary to pursue further investigations, and we conclude with propositions for future work in this context. This should start with a rigorous assessment of existing " natural farming" systems regarding their productivity and environmental benefits, in order to demonstrate its potential before starting projects that promote the system for broader adoption.
  • Authors:
    • Enfors, E.
    • Barron, J.
    • Makurira, H.
    • Rockstrom, J.
    • Tumbo, S.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 11
  • Year: 2011
  • Summary: Yield levels in smallholder farming systems in semi-arid sub-Saharan Africa are generally low. Water shortage in the root zone during critical crop development stages is a fundamental constraining factor. While there is ample evidence to show that conservation tillage can promote soil health, it has recently been suggested that the main benefit in semi-arid farming systems may in fact be an in situ water harvesting effect. In this paper we present the result from an on-farm conservation tillage experiment (combining ripping with mulch and manure application) that was carried out in North Eastern Tanzania from 2005 to 2008. Special attention was given to the effects of the tested treatment on the capacity of the soil to retain moisture. The tested conservation treatment only had a clear yield increasing effect during one of the six experimental seasons (maize grain yields increased by 41%, and biomass by 65%), and this was a season that received exceptional amounts of rainfall (549 mm). While the other seasons provided mixed results, there seemed to be an increasing yield gap between the conservation tillage treatment and the control towards the end of the experiment, and cumulatively the yield increased with 17%. Regarding soil system changes, small but significant effects on chemical and microbiological properties, but not on physical properties, were observed. This raises questions about the suggested water harvesting effect and its potential to contribute to stabilized yield levels under semi-arid conditions. We conclude that, at least in a shorter time perspective, the tested type of conservation tillage seems to boost productivity during already good seasons, rather than stabilize harvests during poor rainfall seasons. Highlighting the challenges involved in upgrading these farming systems, we discuss the potential contribution of conservation tillage towards improved water availability in the crop root zone in a longer term perspective.
  • Authors:
    • Flower, K. C.
    • Jabran, K.
    • Wahid, A.
    • Siddique, K. H. M.
    • Farooq, M.
  • Source: Soil & Tillage Research
  • Volume: 117
  • Year: 2011
  • Summary: Crop yield potential with conservation agriculture (CA) in rainfed systems is often greater than with conventional tillage (CVT) systems, particularly where sub-optimal rainfall limits yield. However, the full potential is rarely achieved because of various biotic and abiotic constraints. Analysis of 25 experiments found a slight increase in CA crop yields over time relative to CVT, indicating that CA can compete with CVT on a purely crop production basis and also has well-established environmental benefits. Evolved weed resistance to herbicides remains one of the greatest challenges to CA yields and long-term sustainability, yet there are some successful management stories. Worldwide adoption of CA is increasing; however, uptake in some regions is slow or non-existent. A lack of information on the effects and interactions of minimal soil disturbance, permanent residue cover, planned crop rotations and integrated weed management, which are key CA components, can hinder its adoption. This is because these interactions can have positive and negative effects depending on regional conditions. The positive impacts should be exploited through systems research to enhance CA crop yields. A greater focus on the influence of residue and weed management components as well as breeding for varieties adapted to biotic and abiotic stresses often associated with CA is required.