• Authors:
    • Perello, A. E.
    • Moreno, V.
    • Chidichimo, H. O.
    • Terrile, I. I.
    • Simon, M. R.
    • Ayala, F. M.
    • Golik, S. I.
    • Cordo, C. A.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 5
  • Year: 2011
  • Summary: Zero tillage often leads to wheat ( Triticum aestivum L.) yield losses from diseases caused by necrotrophic foliar pathogens. The aim of this work was to evaluate the combined effect of tillage, N fertilization, fungicides, and resistant cultivars in reducing foliar disease severity to prevent significant yield losses. A 2-yr study including combinations of (i) conventional and zero tillage; (ii) N fertilization rates 0, 80, or 160 kg ha -1 N; (iii) two fungicide treatments (with and without a fungicide (1 L of metconazole, 9%)) at growth stages (GS) 32 and 39; and (iv) three wheat cultivars was conducted in the Rolling Pampas region in Argentina. The most common foliar disease in the trial was tan spot [ Pyrenophora tritici-repentis (Died.) Drechs.]. Conventional tillage reduced foliar disease severity at GS 23 by 46 and 56% and the area under disease progress curve (AUDPC) by 20 and 14% for each season, respectively compared with zero tillage. The cultivar Buck Bigua had significantly lower AUDPC values than the others. Fungicide and N application reduced disease severity at GS 23 by 35 and 34% respectively, on average over both years. Disease was less severe in zero tillage plots which received a fungicide compared to conventional tillage plots that were not treated with fungicide. In 2002 yields were greater in conventional tillage plots with 160 kg ha -1 N and fungicide application than in all other treatments. In 2003 yields were greatest in zero tillage plots with 160 kg ha -1 N and fungicide. The results of this study indicate that in spite of the increase of necrotrophic diseases, developing no-till systems in wheat monoculture is possible without significant yield losses if effective disease management practices are applied.
  • Authors:
    • Macák, M.
    • Demjanová, E.
    • Smatanová, N.
    • Smatana, J.
  • Source: Research Journal of Agricultural Science
  • Volume: 43
  • Issue: 3
  • Year: 2011
  • Summary: The field experiments was carried out over the period of 2004-2007 at the experimental farm Kalna nad Hronom in south-western Slovakia. The aim of the research was to evaluate the influence of conventional and reduced tillage and management of organic matter on the soil physical characteristics. The sugar beet - spring barley - sunflower - winter wheat crop sequence was evaluated. The soil tillage treatments as follows: T1 - conventional mould board ploughing with farm yard manure application to sugar beet and incorporation of post harvested residues of spring barley and sunflower; T2 - convnentional mould board ploughing; T3 - no-till Horsch CONCORD CO 9. During June soil samples were taken from 0.05-0.10 m, 0.10-0.20 m, 0.20-0.30 m. Total porosity, soil bulk density and soil moisture was evaluated. The differences between soil layer and crops growing in different years were ascertained. Evaluated tillage treatments have no statistical influence on total porosity and soil bulk density in an average of four years. No till treatment (T3) influenced the less infiltration rate of soil profile with comparison to mouldboard ploughing treatments. The soil bulk density was highly significantly influenced by weather condition, growing crops and residue management and significantly influenced by soil layer. The positive effect of FYM on total porosity was evaluated in 2004 during sugar beet phase of rotation in first and second soil layers 0.05-0.10 m (T1 47.47%) and 0.10-0.20 m (46.93%) which is in relationship with soil bulk density 1.266 t.m 3 and 1.279 t.m 3 in topsoil layers 0.5-0.20 m. Soil bulk density range from 1.361-1.52 t.m 3, in an average. Average data of total porosity revealed the significant less total porosity in deeper soil layer 0.2-0.3 m (41.65%) with comparison to top layer 0.05-0.10 m (44.5%). Significantly less total porosity was created under canopy of sunflower (39.9%) with comparison to sugar beet (43.3%), spring barley (43.8%) and winter wheat (45.1%). In four year average results, the conventional mould board ploughing with farm yard manure form the most suitable soil environment (soil bulk density, total porosity and soil humidity retention), but we also recommended no-till for this specific area of Slovak region.
  • Authors:
    • Maul, J. E.
    • Meisinger, J. J.
    • Cavigelli, M. A.
    • Spargo, J. T.
    • Mirsky, S. B.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 90
  • Issue: 2
  • Year: 2011
  • Summary: Sustainable soil fertility management depends on long-term integrated strategies that build and maintain soil organic matter and mineralizable soil N levels. These strategies increase the portion of crop N needs met by soil N and reduce dependence on external N inputs required for crop production. To better understand the impact of management on soil N dynamics, we conducted field and laboratory research on five diverse management systems at a long-term study in Maryland, the USDA- Agricultural Research Service Beltsville Farming Systems Project (FSP). The FSP is comprised of a conventional no-till corn ( Zea mays L.)-soybean ( Glycine max L.)-wheat ( Triticum aestivum L.)/double-crop soybean rotation (NT), a conventional chisel-till corn-soybean-wheat/soybean rotation (CT), a 2 year organic corn-soybean rotation (Org2), a 3 year organic corn-soybean-wheat rotation (Org3), and a 6 year organic corn-soybean-wheat-alfalfa ( Medicago sativa L.) (3 years) rotation (Org6). We found that total potentially mineralizable N in organic systems (average 315 kg N ha -1) was significantly greater than the conventional systems (average 235 kg N ha -1). Particulate organic matter (POM)-C and -N also tended to be greater in organic than conventional cropping systems. Average corn yield and N uptake from unamended (minus N) field microplots were 40 and 48%, respectively, greater in organic than conventional grain cropping systems. Among the three organic systems, all measures of N availability tended to increase with increasing frequency of manure application and crop rotation length (Org2 < Org3 ≤ Org6) while most measures were similar between NT and CT. Our results demonstrate that organic soil fertility management increases soil N availability by increasing labile soil organic matter. Relatively high levels of mineralizable soil N must be considered when developing soil fertility management plans for organic systems.
  • Authors:
    • Kravchenko, A. N.
    • Mokma, D. L.
    • Corbin, A. T.
    • Syswerda, S. P.
    • Robertson, G. P.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 1
  • Year: 2011
  • Summary: Soil C sequestration research has historically focused on the top 0 to 30 cm of the soil profile, ignoring deeper portions that might also respond to management. In this study we sampled soils along a 10-treatment management intensity gradient to a 1-m depth to test the hypothesis that C gains in surface soils are offset by losses lower in the profile. Treatments included four annual cropping systems in a corn ( Zea mays)-soybean ( Glycine max)-wheat ( Triticum aestivum) rotation, perennial alfalfa ( Medicago sativa) and poplar ( Populus * euramericana), and four unmanaged successional systems. The annual grain systems included conventionally tilled, no-tillage, reduced-input, and organic systems. Unmanaged treatments included a 12-yr-old early successional community, two 50-yr-old mid-successional communities, and a mature forest never cleared for agriculture. All treatments were replicated three to six times and all cropping systems were 12 yr post-establishment when sampled. Surface soil C concentrations and total C pools were significantly greater under no-till, organic, early successional, never-tilled mid-successional, and deciduous forest systems than in the conventionally managed cropping system ( p≤0.05, n=3-6 replicate sites). We found no consistent differences in soil C at depth, despite intensive sampling (30-60 deep soil cores per treatment). Carbon concentrations in the B/Bt and Bt2/C horizons were lower and two and three times more variable, respectively, than in surface soils. We found no evidence for C gains in the surface soils of no-till and other treatments to be either offset or magnified by carbon change at depth.
  • Authors:
    • Das, T. K.
    • Tuti, M. D.
  • Source: Indian Journal of Agronomy
  • Volume: 56
  • Issue: 2
  • Year: 2011
  • Summary: Effective weed control in no-till systems is mainly dependent on herbicides. Appropriate weed management strategies, however, can reduce the amount of herbicides. In this study possible weed management was attempted in wheat ( Triticum aestivum L. emend. Fiori & Paol.) under zero-tillage (without residue) and conventional tillage between 2006-07 and 2007-08 following residual effects of 13 weed control treatments with metribuzin applied during previous rainy ( kharif) seasons, 2006 and 2007 in soybean [ Glycine max (L) Mirrill]. The experiment was laid out in a split plot design with three replications. Total density of weeds did not differ significantly between weed control measures adopted during previous rainy season. But, conventional tillage (CT) caused a significant reduction in the populations of grass, broad-leaved (e.g., Chenopodium album L. and Melilotus indica L.) and total weeds when compared with zero-tillage (ZT) without crop residues. Similarly, higher nutrient removal by weeds was under zero-tillage than under conventional tillage. In general, residual effect of all the previous season metribuzin treatments was more pronounced on the grasses ( Phalaris minor Retz. and Avena sterilis ssp. ludoviciana Dur.) when compared with Chenopodium album and Melilotus indica. Wheat yield was similar in all previous season metribuzin treatments except in weed-free check in both years. However, metribuzin at 0.5 kg/ha pre-emergence, on yield, was more effective, indicating its considerable residual effect on weeds in wheat. This treatment also gave the highest net benefit:cost ratio.
  • Authors:
    • Wu, Z. J.
    • Zhu, A. N.
    • Chen, L. J.
    • Chen, Z. H.
    • Wang, J. B.
  • Source: Plant, Soil and Environment
  • Volume: 57
  • Issue: 6
  • Year: 2011
  • Summary: The effects of tillage and residue input amounts on soil phosphatase (alkaline phosphomonoesterase ALP, acid phosphomonoesterase ACP, phosphodiesterase PD, and inorganic pyrophosphatase IPP) activities and soil phosphorus (P) forms (total P, organic P, and available P) were evaluated using soils collected from a three-year experiment. The results showed that no-till increased soil total and organic P, but not available P as compared to conventional tillage treatments. Total P was increased as inputs of crop residue increased for no-till treatment. There were higher ALP and IPP activities in no-till treatments, while higher PD activity was found in tillage treatments and tillage had no significant effect on ACP activity. Overall phosphatase activities increased with an increase of crop residue amounts. Soil total P was correlated negatively with PD activity and positively with other phosphatase activities. Organic P had a positive correlation with ACP activity, but a negative correlation with PD activity. Available P had no significant correlation with phosphatase activities. Our data suggests that no-till and residue input could increase soil P contents and enhance the activities of phosphatase.
  • Authors:
    • Miller, P.
    • Lawrence, R. L.
    • Watts, J. D.
    • Montagne, C.
  • Source: Climactic Change
  • Volume: 108
  • Issue: 1/2
  • Year: 2011
  • Summary: A pilot cropland carbon sequestration program within north central Montana has allowed farmers to receive carbon credit for management adjustments associated with changing from tillage-based agricultural systems to no-till. Carbon credit can also be obtained by adopting conservation reserve, where cropland is planted into perennial vegetation. Summer fallowing is also considered within the crediting process as credit is not given in years that a field is left un-vegetated. The carbon sequestration program has been advocated as a means to mitigate climate change while providing an added source of income for Montana farmers. There is lack of data, however, pertaining to the percentage of lands within this region that have not converted to no-till management, lands under certain crop intensities (e.g. those that are cropped every growing season vs. those that use a fallow-crop-fallow system), or cropland that have converted to perennial vegetation outside of the popular Conservation Reserve Program. Data is also sparse concerning the amount of soil organic carbon that might be sequestered given a conversion to no-till or conservation reserve. This study established regional percentage estimates of cropland under no-till, various degrees of crop intensity, and conservation reserve within north central Montana. Literature-based carbon sequestration estimates were used to generate carbon gain data associated with the conversation to no-till and to conservation reserve. These estimates were then applied to the area-based cropland statistics to estimate potential regional carbon sequestration associated with these management changes.
  • Authors:
    • Xie, J.
    • Li, L.
    • Huang, G.
    • Cai, L.
    • Luo, Z.
    • Zhang, R.
  • Source: Acta Prataculturae Sinica
  • Volume: 20
  • Issue: 4
  • Year: 2011
  • Summary: Long-term field experiments on soil physical quality in rainfed farming systems were conducted in Dingxi on the western Loess Plateau. The effects of conventional tillage and five conservation agriculture patterns [conventional tillage (T), conventional tillage with stubble incorporation (TS), no till with no stubble (NT), no till with stubble retention (NTS), conventional tillage with plastic mulching (TP) and no till with plastic mulching (NTP)] were studied. The experiment was fully-phased with two rotation sequences. Phase 1 started with field pea ( Pisum sativum) followed by spring wheat ( Triticum aestivum) (P->W) whereas phase 2 started with spring wheat followed by field pea (W->P). There were highly significant differences between the six tillage measures in soil properties including soil aggregates, available water content, water use efficiency and saturation conductivity. There were also significant differences in some soil properties including soil bulk density, total porosity, capillary porosity, non-capillary porosity, soil strength and saturation capacity. There were no significant differences in soil properties such as soil temperature and field capacity. Using the addition and multiplication method, and weighted integrated method, quantitative assessments of soil physical quality in different tillage systems were carried out. The order of soil physical quality index from high to low was NTS, NTP, NT, TS, T(TP) and TP(T) in P->W rotation, and NTS, NTP, TS, NT, TP and T in W->P rotation. The various tillage measures resulted in very different soil physical quality levels. Improved soil structure arose from tillage reduction or residue retention which improved soil structure, enhanced water infiltration, reduced soil and water loss, and hence improved soil physical quality.
  • Authors:
    • Li, Z.
    • Liu, W. Z.
    • Zhang, X. C.
    • Chen, J.
  • Source: Agricultural and Forest Meteorology
  • Volume: 151
  • Issue: 10
  • Year: 2011
  • Summary: Trends and uncertainty of the climate change impacts on hydrology, soil erosion, and wheat production during 2010-2039 at El Reno in central Oklahoma, USA, were evaluated for 12 climate change scenarios projected by four GCMs (CCSR/NIES, CGCM2, CSIRO-Mk2, and HadCM3) under three emissions scenarios (A2, B2, and GGa). Compared with the present climate, overall t-tests ( n=12) show that it is almost certain that mean precipitation will decline by some 6% (>98.5% probability), daily precipitation variance increase by 12% (>99%), and maximum and minimum temperature increase by 1.46 and 1.26 degrees C (>99%), respectively. Compared with the present climate under the same tillage systems, it is very likely (>90%) that evapotranpiration and long-term soil water storage will decease, but runoff and soil loss will increase despite the projected declines in precipitation. There will be no significant changes in wheat grain yield. Paired t-tests show that daily precipitation variance projected under GGa is greater than those under A2 and B2 ( P=0.1), resulting in greater runoff and soil loss under GGa ( P=0.1). HadCM3 projected greater mean annual precipitation than CGCM2 and CSIRO ( P=0.1). Consequently, greater runoff, grain yield, transpiration, soil evaporation, and soil water storage were simulated for HadCM3 ( P=0.1). The inconsistency among GCMs and differential impact responses between emission scenarios underscore the necessity of using multi-GCMs and multi-emission scenarios for impact assessments. Overall results show that no-till and conservation tillage systems will need to be adopted for better soil and water conservation and environmental protection in the region during the next several decades.
  • Authors:
    • Shen, Y.
    • Wang, X.
    • Zheng, L.
  • Source: Acta Prataculturae Sinica
  • Volume: 20
  • Issue: 4
  • Year: 2011
  • Summary: The research presented crop yield, phosphorus dynamic for a wheat-soybean rotation systems affected by tillage management: conventional tillage (t), tillage+ stubble retention (ts), no-till (nt), no-till+stubble retention (nts) in the Loess Plateau. Results showed that ten years tillage management implementation did not carry a yield penalty for winter wheat, soybean yield had a positive response to conservation tillage. Soil phosphorus content increased with the increasing of rotation sequences. Both total phosphorus and available phosphorus contents were increased at top 0-5 cm. Stubble retention increase crop phosphorus uptake, P contents in soybean grain under nts and ts treatment were 111% and 82% higher than that under t treatment. The results provide a local agricultural implement provides certain theoretical guidance.