• Authors:
    • Altieri, M. A.
    • Lana, M. A.
    • Bittencourt, H. V.
    • Kieling, A. S.
    • Comin, J. J.
    • Lovato, P. E.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 8
  • Year: 2011
  • Summary: In Santa Catarina, southern Brazil, family farmers modified the conventional no-till system by flattening cover crop mixtures on the soil surface as a strategy to reduce soil erosion and lower fluctuations in soil moisture and temperature, improve soil quality, and enhance weed suppression and crop performance. During 2007 and 2008, we conducted three experiments aimed at understanding the processes and mechanisms at play in successful organic conservation tillage systems (OCT), especially the underpinnings of ecological weed suppression, a key advantage of OCT systems over conventional no-till systems. Our results, as well as farmers observations, suggest that cover crops can enhance weed suppression and hence crop productivity through physical interference and allelopathy and also a host of effects on soil quality, fertility, and soil moisture that we did not measure. Results from the three trials indicate that the best cover crop mixture should include a significant proportion of rye, vetch, and fodder radish as these mixtures produce large biomass, and are readily killed by rolling forming a thick mulch sufficient to provide effective weed control in the subsequent vegetable crop.
  • Authors:
    • Alletto, L.
    • Coquet, Y.
    • Justes, E.
  • Source: Agricultural Water Management
  • Volume: 102
  • Issue: 1
  • Year: 2011
  • Summary: Effects of two tillage treatments and two fallow period managements under continuous maize cropping on soil temperature, soil water dynamics and maize development were evaluated over a 4-year period (2005–2008). Tillage treatments were conventional tillage with mouldboard ploughing and conservation tillage with disk harrowing. The fallow period managements were bare soil or soil sown with a cover crop after maize harvest. For each year, topsoil temperature (0–20 cm-depth) was lower under conservation tillage systems at sowing, from 0.8 to 2.8 °C. This difference persisted several weeks after sowing, and disappeared afterwards. Under conservation tillage, higher soil water content was generally measured at sowing and during the growing season strong fluctuations were observed at 40 cm-depth. Under conventional tillage, soil water content varied mainly in the tilled layer (20 cm-depth). Tillage and fallow period management affected water flow rate at 40 cm-depth. During the maize growing season, the lowest drainage volumes were measured in 2006 and 2008 under conservation tillage in cover cropped plots. No effect of fallow period management on maize development and yield was observed but significantly higher yields were measured under conservation tillage in 2005 and 2007. From this 4-year experiment under continuous maize cropping, using cover crop and reducing tillage intensity enhanced water use efficiency while maintaining or increasing maize yields.
  • Authors:
    • Cockfield, G.
    • Maraseni, T. N.
  • Source: Agricultural Systems
  • Volume: 104
  • Issue: 6
  • Year: 2011
  • 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:
    • Cociu, A. I.
    • Alionte, E.
  • Source: Analele Institutului National de Cercetare-Dezvoltare Agricola Fundulea
  • Volume: 79
  • Issue: 2
  • Year: 2011
  • Summary: Grain yields of winter wheat (Triticum aestivum L.), maize ( Zea mays L.), and soybean [ Glycine max. (L.) Merr], in rotation were significantly influenced by soil deep loosening and tillage system, depending on water supply (irrigation application). Scientific literature regarding the influence of these agronomic factors on the yield quality of the respective three crops, in rotation, is quite limited. For this study, a field experiment was carried out at Fundulea, which is located in the eastern part of the Danube Plain, on a cambic chernozem soil type. One of the main objectives was to determine how the grain yield quality of winter wheat, maize and soybean is influenced by different reduced tillage systems, in comparison with the traditional (conventional) one, as well as by the direct seeding in non-worked ground, or in strip till, with and without soil deep loosing, under different irrigations. Regarding the maize, the water provisioning * tillage system interaction was very significant (P0.05). Under the three water provisions applied, protein content had values between 40.0%, recorded when the normal irrigation rate was used, at no till system, and 41.5%, recorded for the dry conditions, also at no till system. The 1,000 kernel weight varied between 120 g, registered for the dry conditions at no till variant, and 159 g, registered for normal irrigation rate, also at no till system. The results of this research do not make evident a certain tendency of protein content, but show clearly that the fat content increases concomitantly with grain yield growing. As concerns the winter wheat crop, the water provisioning * tillage system interaction was not significant (P>0.05). Protein content was comprised between 13.2%, registered when the normal irrigation rate was applied at no till system variant, and 15.7%, under dry conditions, at the traditional tillage system. The minimum value of 1,000 kernel weight was 37 g, recorded for dry conditions at chisel tillage variant, and the highest value, of 47 g, was obtained when normal irrigation rate was applied to no till variant.
  • 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:
    • 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:
    • 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.