• Authors:
    • Miyao, G.
    • Jackson, J.
    • Mitchell, J. P.
    • Horwath, W. R.
    • Doane, T. A.
    • Brittan, K.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 85
  • Issue: 3
  • Year: 2009
  • Summary: In spite of potential benefits and positive assessments of reducing primary tillage operations, only a small part of irrigated row crops is currently managed using reduced tillage, for reasons that include concerns about its agronomic suitability for certain crop rotations. Three years of a tomato/corn rotation under standard and no-tillage management were used to understand the fate of a fertilizer and cover crop nitrogen (N) application. Uptake of both inputs was reduced under no-tillage during the year of application, in this case a tomato crop. As a result, more input N was retained in the soil in this system. The initial challenge of reduced tomato yields diminished as no-tillage management remained in place and the soil N reservoir developed. Corn production was not affected by tillage treatment. Inclusion of a legume cover crop increased the amount of fertilizer N retained in the soil over time, more so under no-tillage than under standard tillage, emphasizing the benefit of cover crops in reducing the amount of fertilizer required to maintain productivity. While acceptance of reduced tillage ultimately depends on economic performance, the results of this study support its agronomic viability for irrigated row crops.
  • Authors:
    • Ralisch, R.
    • Nakashima, P.
    • Gasparetto, N. V. L.
    • Domingos, M. M. M.
    • Tavares Filho, J.
  • Source: Revista Brasileira de Ciência do Solo
  • Volume: 33
  • Issue: 6
  • Year: 2009
  • Summary: Structural changes caused by management systems to soil can result in compaction and may change crop root development. With the aim to evaluate the effects of the farming systems on the soil structure by qualitative (cultural profile) and quantitative (soil density) methodologies, a field study was carried out in Maringa, state of Parana, Brazil (23degrees29′S, 51degrees59′W). A conventional tillage system with crop succession of corn ( Zea mays L.) and soybean ( Glycine max) and a no-till system with crop rotation of wheat ( Triticum spp.), corn ( Zea mays L.), common bean ( Phaseolus vulgaris), black oats ( Avena strigosa), and soybean ( Glycine max) established for more than 20 years were evaluated. An area under natural forest near the experimental field was evaluated as reference. After the description of the cultural (soil) profile, deformed samples were collected from the homogeneous soil volumes: two samples under forest, two samples in the no-till system and three samples in the conventional system. The physical and morphologic analyses of the soil structures of the layers 0-20 and 20-40 cm showed: (a) the two different tillage system promoted distinct depths of anthropic horizons; (b) the soil structure affected root distribution; (c) soil compaction under conventional system occurred in vertical and horizontal directions (d) soil structure was best under the no-till system; (e) the cultural profile methodology is efficient in soil morphology evaluations.
  • Authors:
    • Sabau, N. C.
    • Domuta, C.
    • Borza, I.
    • Bandici, G.
    • Samuel, A.
    • Ciobanu, C.
    • Ardelean ,I.
    • Ciobanu, G.
    • Sandor, M.
    • Domuta, C.
    • Brejea, R.
    • Vuscan, A.
  • Source: Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Agriculture
  • Volume: 66
  • Issue: 1
  • Year: 2009
  • Summary: Field studies were conducted in Oradea, Romania, from 2003 to 2008, in a long term trial placed in 1990 on preluvosoils. The climate indicator de Martonne aridity index (IdM) was used for quantification of the correlation between climate and wheat yield in unirrigated and irrigated conditions and a new class called arid was used for climate index characterization. Maintaining the soil water reserve on 0-50 cm depth between easily available water content and field capacity using the irrigation determined the increase of the IdM values for period IV-VI with 79% in 2003, 73% in 2004, 36% in 2005, 16% in 2006, 162% in 2007 and with 131% in 2008. Using the irrigation and the improvement of the microclimate conditions determined to obtain the yield gains, showed very significant results every year and every crop rotation studied, both in unirrigated and irrigated conditions. The smallest wheat yields were obtained in monocrop and the biggest in the wheat-maize-soyabean rotation. In the all 3 rotations, the direct links statistically assured were registered between the values of the IdM and yields in unirrigated and irrigated wheat. These correlations sustained the need of the irrigation in wheat from Crisurilor Plain. Correlation between the IdM was stronger in the wheat-maize-soyabean rotation compared to the wheat-maize rotation and with wheat monocrop. As a consequence, rotation of wheat-maize-soyabean was recommended because the climate and microclimate conditions were better used.
  • Authors:
    • Joshi, O. P.
    • Billore, S. D.
    • Dupare, B. U.
    • Verma, S. K.
  • Source: Soybean Research
  • Volume: 7
  • Year: 2009
  • Summary: A study was conducted to visualize the impact of soybean cultivation in the "Soya State", Madhya Pradesh. The data were collected using well-designed interview schedule containing relevant questions on how soybean has affected farmers lifestyle as well as overall farming scenario? Majority of the respondents perceived soybean cultivation as a major driving force for their socio-economic development. A steady increase in the farmers' inclination to grow soybean was observed during the last five decades, while, decreasing their area in traditionally grown crops like sorghum, pigeon pea, groundnut, cotton and black gram. During soybean introduction many changes in the overall farming scenario of Madhya Pradesh have occurred. The change was recorded in the land holding pattern of farmers which revealed that small and marginal farmers have further reduced their land holdings while larger farmers have not only managed their holdings but also added newer areas to their total farm size. The cost of cultivation as well as rates fetched by the soybean showed an upward trend with passage of time during these five decades. An inverse relationship between the labour availability and wages was also observed. The gathered opinion from farmers brought out that fertilizer consumption and insect-load appeared to have increased with time. It seems that in spite the irrigation facilities have increased during these 50 years, particularly that of canal, tube wells and ponds, soybean by and large, remained to be a rainfed crop. However, the farmers have shifted from bullock drawn implements to tractor drawn implements. This led to limiting number of animals with farmers, thereby progressive reduction in the use of manures. Subsequent to the introduction of soybean, the socio-economic status of the farmers has improved.
  • Authors:
    • Durán Zuazo, V. H.
    • Rodríguez Pleguezuelo, C. R.
    • Arroyo Panadero, L.
    • Martínez Raya, A.
    • Francia Martínez, J. R.
    • Cárceles Rodríguez, B.
  • Source: Pedosphere
  • Volume: 19
  • Issue: 4
  • Year: 2009
  • Summary: Sloping and mountainous olive production systems are widespread, occupying large parts of the Mediterranean landscape prone to water erosion. Soil erosion, runoff, and soil water content patterns over a three-year period were monitored in erosion plots on a mountainside with rainfed olive (Olea europaea cv. Picual) trees under: 1) non-tillage with barley strips of 4 m width (BS); 2) non-tillage with native vegetation strips of 4 m width (NVS); and 3) non-tillage without plant strips (NT). The erosion plots, located in Lanjaron (Granada, south-eastern Spain), on a 30% slope, were 192 m(2) in area. For assessing soil water dynamics in real-time and near-continuous soil water content measurements, multisensor capacitance probes were installed in the middle of plant strips and beneath the olive tree at five soil depths (10, 20, 30, 50, and 100 cm). The highest erosion and runoff rates were measured under NT, with a mean of 17.3 Mg ha(-1) year(-1) and 140.0 mm year(-1), respectively, over the entire study period. The BS and NVS with respect to the NT reduced erosion by 71% and 59% and runoff by 95% and 94%, respectively. In general, greater available soil water content was found under BS than NVS and NT, especially beneath the olive tree canopies. These results supported the recommendation of non-tillage with barley strips in order to reduce erosion and to preserve soil water for trees in traditional mountainous olive-producing areas, where orchards cover vast tracts of land.
  • Authors:
    • Beber Vieira, F. C.
    • Zanatta, J. A.
    • Piccolo, M. d. C.
    • Costa, F. d. S.
    • Bayer, C.
    • Gomes, J.
    • Six, J.
  • Source: Soil & Tillage Research
  • Volume: 106
  • Issue: 1
  • Year: 2009
  • Summary: It has been shown that cover crops can enhance soil nitrous oxide (N(2)O) emissions, but the magnitude of increase depends on the quantity and quality of the crop residues. Therefore, this study aimed to evaluate the effect of long-term (19 and 21 years) no-till maize crop rotations including grass [black oat (Avena strigosa Schreb)] and legume cover crops [vetch (Vigna sativa L), cowpea (Vigna unguiculata L. Walp), pigeon pea (Cajanus cajan L. Millsp.) and lablab (Dolichos lablab)] on annual soil N(2)O emissions in a subtropical Acrisol in Southern Brazil. Greater soil N(2)O emissions were observed in the first 45 days after the cover crop residue management in all crop rotations, varying from -20.2 +/- 1.9 to 163.9 +/- 24.3 mu g N m(-2) h(-1). Legume-based crop rotations had the largest cumulative emissions in this period, which were directly related to the quantity of N (r(2) = 0.60, p = 0.13)and inversely related to the lignin:N ratio(r(2) = 0.89,p = 0.01) of the cover crop residues. After this period, the mean fluxes were smaller and were closely related to the total soil N stocks (r(2) = 0.96, p = 0.002). The annual soil N(2)O emission represented 0.39-0.75% of the total N added by the legume cover crops. Management-control led soil variables such as mineral N (NO(3)(-) and NH(4)(+)) and dissolved organic C influenced more the N(2)O fluxes than environmental-related variables as water-filled pore space and air and soil temperature. Consequently, the synchronization between N mineralization and N uptake by plants seems to be the main challenge to reduce N(2)O emissions while maintaining the environmental and agronomic services provided by legume cover crops in agricultural systems. (C) 2009 Elsevier B.V. All rights reserved.
  • Authors:
    • Kpomblekou-A, K.
    • Hamido, S. A.
  • Source: Soil & Tillage Research
  • Volume: 105
  • Issue: 2
  • Year: 2009
  • Summary: Increasing numbers of vegetable growers are adopting conservation tillage practices and including cover crops into crop rotations. The practice helps to increase or maintain an adequate level of soil organic matter and improves vegetable yields. The effects of the practices, however, on enzyme activities in southeastern soils of the United States have not been well documented. Thus, the objectives of the study were to investigate the effects of cover crops and two tillage systems on soil enzyme activity profiles following tomato and to establish relationships between enzyme activities and soil organic carbon (C) and nitrogen (N). The cover crops planted late in fall 2005 included black oat (Avena strigosa), crimson clover (Trifolium incarnatum L.), or crimson clover-black oat mixed. A weed control (no cover crop) was also included. Early in spring 2006, the plots were disk plowed and incorporated into soil (conventional tillage) or mowed and left on the soil surface (no-till). Broiler litter as source of N fertilizer was applied at a rate of 4.6 Mg ha(-1), triple super phosphate at 79.0 kg P ha(-1), and potassium chloride at 100 kg K ha(-1) were also applied according to soil testing recommendations. Tomato seedlings were transplanted and grown for 60 days on a Marvyn sandy loam soil (fine-loamy, kaolinitic, thermic Typic Kanhapludults). Ninety-six core soil samples were collected at incremental depths (0-5, 5-10, and 10-15 cm) and passed through a 2-mm sieve and kept moist to study arylamidase (EC 3.4.11.2), L-asparaginase (EC 3.5.1.1), L-glutaminase (EC 3.5.1.2), and urease (EC 3.5.1.5) activities. Tillage systems affected only L-glutaminase activity in soil while cover crops affected activities of all the enzymes studied with the exception of urease. The research clearly demonstrated that in till and no-till systems, L-asparaginase activity is greater (P
  • Authors:
    • Albayrak, S.
    • Oz, M.
    • Bilgili, U.
    • Wietgrefe, G.
    • Tongel, O.
    • Karasu, A.
    • Sincik, M.
    • Acikgoz, E.
    • Turan, Z. M.
    • Goksoy, A. T.
  • Source: Field Crops Research
  • Volume: 110
  • Issue: 3
  • Year: 2009
  • Summary: Despite several experiments on row spacings and seeding rates of grain soybeans, limited information is available on the most suitable row spacing and seeding rate for tall and robust forage type soybeans grown for seed. The objectives of this study were to investigate seed yield, oil and protein content, and several morphological traits as affected by row spacing (20, 40, 60 and 80 cm) and seeding rate (330,000, 660,000, 990,000 and 1,320,000 seeds ha -1) in tall and robust forage type soybeans in three irrigated Mediterranean environments in Turkey in a randomized split plot design with three replications in 2004 and 2005. Row spacings had no significant effect on plant height but tall and profusely branched plants developed in wide row spacing and light seeding conditions. Seed yield responded positively and linearly to row spacing up to 60 cm and then decreased slightly in all locations. Seed yield was the highest at 990,000 seeds ha -1 seeding rate in all three locations (3072.5 kg ha -1 in Bursa LSD=214.7 kg ha -1, 3295.1 kg ha -1 in Mustafakemalpasa LSD=298.6 kg ha -1 and 3311.3 kg ha -1 in Samsun LSD=321.1 kg ha -1). Averaged across years, locations, row spacings, and seeding rates the mean seed yield was an impressive 3013.4 kg ha -1 compare with 3500.0 kg ha -1 average seed yield of grain types. Crude protein and oil content of forage type soybean were not significantly affected by row spacings and seeding rates. It was concluded that forage type soybeans can be grown for multiple purposes at the 990,000 seeds ha -1 seeding rate and 60 cm row spacings in Mediterranean environments.
  • Authors:
    • de Alba, S.
    • Benito, G.
    • Lacasta, C.
    • Alcázar, M.
    • Alba, S. de
  • Source: Advances in Geoecology or Land degradation and rehabilitation: dryland ecosystems. Papers presented at the Fourth International Conference on Land Degradation, Cartagena, Murcia, Spain, 12-17 September 2004.
  • Volume: 40
  • Year: 2009
  • Summary: In Europe, especially in the Mediterranean area, water erosion seriously affects 50% to 70% of agricultural land. However, there is a lack of field-data on water erosion rates for agricultural areas in semiarid Mediterranean climates. This paper describes an experimental field station (La Higueruela Station) for the continuous monitoring of water erosion that was set up in 1992 in central Spain (Toledo, Castilla-La Mancha). In the study area, the annual precipitation is around 450 mm with a very irregular inter-annual and seasonal distribution, which includes a strong drought in summer. The geology is characterized by non-consolidated Miocene materials, mostly arcosics. The area presents a low relief and gentle slopes, generally
  • Authors:
    • Steinbach, H. S.
    • Alvarez, R.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: The Argentine Pampas is one of the most important cropping regions of the World. Limited tillage systems, and specially no-till, had widespread in recent years, occupying actually around 70% of the surface devoted to annual crops. We review results produced in field experiments installed along the Pampas to determine the effect of the adoption of these tillage systems on some soil properties and crops yield. It was performed a meta-analysis of data from experiments where plow tillage (mouldboard plow), reduced tillage (chisel plow, disk plow or harrow disk) and no-till were compared. Treatments effects were contrasted by paired t-tests between groups of paired data. Soil bulk density and cone penetration resistance of the 0-20 cm layer were higher under limited tillage systems than under plow tillage. Increases of bulk density under no-till in comparison to plow tillage were generally small, averaging 4%, but cone penetration increased by 50% in many soils. The increase of bulk density was greater in soils of initial low bulk density. Neither bulk density increases nor cone penetration changes reached critical threshold for roots development. Aggregate stability and water infiltration rate were higher in soils subjected to limited tillage systems than under plow tillage. The improvement of aggregate stability was higher in poorer structured soils, with an average increase of 70% under no-till in relation to plow tillage. Under no-till infiltration rate doubled in average that of plow tillage. Soil water content during the critical periods of sowing and flowering was generally greater under limited tillage but, conversely, nitrate nitrogen levels were greater in plow tillage. Higher soil water content under no-till in relation to plow tillage may satisfied the evapotranspiration demand of 1-3 days of crops during the critical flowering period, being nitrate nitrogen in average 21 kg ha -1 lower under no-till. Soybean ( Glycine max (L.)-Merr.) yield was not affected by tillage system, meanwhile wheat ( Triticum aestivum L.) and corn ( Zea mays L.) yields were lower under reduced tillage and no-till than under plow tillage without nitrogen fertilization. Wheat and corn no-till yields were 10-14% lower that yields under plow tillage as a mean. When fertilizers were applied, wheat and corn yield differences between tillage treatments generally disappeared. The adoption of limited tillage systems in the Pampas leads to soil improvement but also generates the necessity of increase nitrogen fertilizers utilization to sustain yields of graminaceus crops.