• Authors:
    • Roger-Estrade, J.
    • Basch, G.
    • Moreno, F.
    • Soane, B. D.
    • Ball, B. C.
    • Arvidsson, J.
  • Source: Soil & Tillage Research
  • Volume: 118
  • Year: 2012
  • Summary: Recent literature on no-till is reviewed with particular emphasis on research on commercial uptake and environmental concerns in northern, western and south-western Europe. Increased interest in no-till, and minimum or reduced tillage, results from changes in the economic circumstances of crop production, the opportunity to increase the area of more profitable autumn-sown crops and increased concern about environmental damage associated with soil inversion by ploughing. Highly contrasting soil and climate types within and between these regions exert a strong influence on the success of no-till. While no-till may often result in crop yields which equal or exceed those obtained after ploughing, modest reductions in yield may be tolerated if production costs are lower than with ploughing. The relative costs of fuel and herbicides have changed appreciably in recent years making no-till more attractive commercially. While effective weed control is an essential aspect of no-till, current herbicide technology may not yet fully achieve this. In northern regions no-till usually allows earlier drilling of winter-sown crops but will give lower soil temperature and higher moisture content in spring, causing delayed drilling of spring-sown crops. No-till soils have greater bulk density and bearing capacity than ploughed soils with a pronounced vertical orientation of macroporosity allowing penetration of roots and water, especially in view of the increased population of deep-burrowing earthworms. Particular care must be taken with no-till to minimise soil damage at harvest and to ensure the even distribution of crop residues prior to drilling. Reduced erosion and runoff after adoption of no-till are widely observed and are of particular importance in southwestern Europe. No-till reduces losses of phosphorus in runoff and, in some cases, reduces the loss of nitrate through leaching. Emissions of greenhouse gases CO 2 and N 2O from no-till soils are highly variable and depend on complex interactions of soil properties. Emission of CO 2 from fuel during machinery usage is always appreciably reduced with no-till. Increased soil organic carbon in surface layers of no-till soils is widely found but may not be associated with increased carbon sequestration throughout the profile. The evaluation of the relative carbon balance for no-till and ploughing depends upon complex inter-relationships between soil and climate factors which are as yet poorly understood. Adoption of no-till could be encouraged by government financial assistance in recognition of environmental benefits, although future restrictions on the use of herbicides may be a deterrent. Opportunities for further research on no-till are outlined.
  • Authors:
    • Ugarte, D. G. de la T.
    • English, B. C.
    • Roberts, R. K.
    • Larson, J. A.
    • Toliver, D. K.
    • West, T. O.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 2
  • Year: 2012
  • Summary: This research evaluated differences in yields and associated downside risk from using no-till and tillage practices. Yields from 442 paired tillage experiments across the United States were evaluated with respect to six crops and environmental factors including geographic location, annual precipitation, soil texture, and time since conversion from tillage to no-till. Results indicated that mean yields for sorghum [ Sorghum bicolor (L.) Moench] and wheat ( Triticum aestivum L.) with no-till were greater than with tillage. In addition, no-till tended to produce similar or greater mean yields than tillage for crops grown on loamy soils in the Southern Seaboard and Mississippi Portal regions. A warmer and more humid climate and warmer soils in these regions relative to the Heartland, Basin and Range, and Fruitful Rim regions appear to favor no-till on loamy soils. With the exception of corn ( Zea mays L.) and cotton ( Gossypium hirsutum L.) in the Southern Seaboard region, no-till performed poorly on sandy soils. Crops grown in the Southern Seaboard were less likely to have lower no-till yields than tillage yields on loamy soils and thus had lower downside yield risk than other farm resource regions. Consistent with mean yield results, soybean [ Glycine max (L.) Merr.] and wheat grown on sandy soils in the Southern Seaboard region using no-till had larger downside yield risks than when produced with no-till on loamy soils. The key findings of this study support the hypothesis that soil and climate factors impact no-till yields relative to tillage yields and may be an important factor influencing risk and expected return and the adoption of the practice by farmers.
  • Authors:
    • Divito, G.
    • Sainz Rozas, H.
    • Echeverria, H.
    • Wyngaard, N.
  • Source: Soil & Tillage Research
  • Volume: 119
  • Year: 2012
  • Summary: Agricultural management practices, such as tillage and fertilization alter soil physical, chemical and biological properties over the medium term, which has a direct impact on the system's sustainability and crop performance. The aim of this work was to evaluate how fertilization with nitrogen (N), phosphorus (P), sulphur (S), micronutrients (Mi), liming (Li) and tillage systems affect soil properties in the medium term, and to measure the impact of these changes on maize ( Zea mays L.) yield. A seven-year experiment on a Typic Argiudoll in the Southern Pampas region of Argentina using seven fertilizations treatments (Control, N P, NS, PS, NPS, NPS+Mi, and NPS+Mi+Li) and two tillage systems - conventional tillage (CT) and no-till (NT) - was evaluated. Each sub-plot was analyzed to determine physical parameters - bulk density (BD) and aggregate stability (AS)-, biological parameters - total organic carbon (TOC), carbon in the particulate fraction (COP), anaerobically incubated nitrogen (AN), total nitrogen (TN) and nitrogen in the particulate fraction (PN) - and chemical parameters - nitrate, available phosphorus, sulphate and pH - at different depths. Also, maize yield was measured in the final year without fertilizer application, in order to evaluate the effects of soil changes on this crop. Among the physical parameters, the only differences found were in BD between tillage systems in the 0-5 cm layer (1.28 g cm -3 in NT and 1.15 g cm -3 in CT). Biological parameters were unaffected by fertilization treatments. However, tillage systems modified many of them in the 0-5 cm layer: COT (17 Mg ha -1 in CT and 21 Mg ha -1 in NT), POC (2.4 Mg ha -1 in CT and 4.5 Mg ha -1 in NT), TN (1.4 Mg ha -1 in CT and 1.8 Mg ha -1 in NT), PN (0.3 Mg ha -1 in CT and 0.5 Mg ha -1 in NT) and AN (56 mg kg -1 in CT and 79 mg kg -1 in NT). These differences were not significant when the 5-20 cm depth was analyzed. Chemical properties such as pH (5.7 in treatments with N; 6.1 without N, and 6.4 with N and lime) and P Bray content were modified (35 mg kg -1 in treatments with P and 13 mg kg -1 without P). In both cases, there was interaction with the tillage system, with significant stratification under NT. Maize yield was only affected by residual P; there were no other effects of medium-term fertilization or tillage systems.
  • Authors:
    • Lee, Y.
    • Kwak, Y.
    • Lee, S.
    • Choi, K.
    • Seo, Y.
    • Kim, M.
    • Yang, S.
  • Source: World Journal of Microbiology and Biotechnology
  • Volume: 28
  • Issue: 4
  • Year: 2012
  • Summary: The present study evaluated the changes of soil microbial communities that were subjected to no-till and compared the results to those subject to tillage for organic farming in a controlled horticultural field by fatty acid methyl ester. Fungi ( P<0.001), gram-positive bacteria ( P<0.001), arbuscular mycorrhizal fungi ( P<0.01), and actinomycetes ( P<0.01) in the no-till soils were significantly larger than those in the tillage soils. The no-till in the subsoil had a significantly lower ratio of cy17:0 to 16:1omega7c compared to that of tillage, indicating that microbial stress decreased because the soils were not disturbed ( P<0.05). Fungi should be considered as a potential factor responsible for the obvious microbial community differentiation that was observed between the no-till and tillage areas in a controlled horticultural field.
  • Authors:
    • Alldredge, J. R.
    • Long, D. S.
    • Young, F. L.
  • Source: Crop Management
  • Issue: March
  • Year: 2012
  • Summary: Growers are becoming interested in producing canola ( Brassica napus or B. rapa) in the dryland, wheat-fallow region of the Pacific Northwest. Currently, agronomic research for spring canola in this region has not been initiated. This study evaluated the effect of no-till planting methods on stand establishment, crop yield, and seed oil quantity of spring canola in Washington and Oregon in 2009 and 2010. The treatments included: double disk opener; broadcast; broadcast plus rolled; Kile opener; Cross-Slot opener; and hoe opener (at Washington only). In this study, canola establishment was generally greatest with the double disk opener and least in the broadcast or broadcast plus rolled treatments at all four site-years. Yield was least in the broadcast treatment and rolling broadcast seed increased yield only 50% of the time. In three out of four site-years, canola planted with the various no-till openers yielded higher than broadcast seed. The adoption of spring canola in the wheat-fallow region of the Pacific Northwest would improve pest management strategies, diversify markets, and increase sustainability.
  • Authors:
    • Li, F.
    • Gan, Y.
    • Li, X.
    • Si, J.
    • Xiong, Y.
    • Liu, C.
    • Jin, S.
    • Zhou, L.
  • Source: Field Crops Research
  • Volume: 126
  • Year: 2012
  • Summary: Understanding plant-soil relationships may help maximize crop productivity while maintaining and improving soil quality. Field experiments were conducted in 2006 and 2007 at the Dryland Agricultural Experimental Station of the Loess Plateau, Lanzhou University, China, to determine the effects of various ridge-furrow and plastic-mulching techniques on the growth and yield of maize ( Zea mays L.) and soil biochemical properties. Five treatments were designed: (1) flat-plot sowing without ridge-furrow mulching (CK), (2) large (80 cm) and small (40 cm) ridges alternated and fully mulched with plastic (DRM), (3) on-furrow sowing with plastic mulch applied only on the ridge at a row spacing of 60 cm and 40 cm alternatively (RM), (4) flat-plot sowing with plastic mulch at a row spacing of 60 cm and 40 cm alternatively (NM), and (5) flat-plot sowing with plastic mulch at a row spacing of 80 cm and 40 cm alternatively (WM). The results showed that film mulching enhanced soil microbial biomass; where microbial biomass carbon (MBC) in the DRM treatment reached 633 mg kg -1 at harvest in 2007, three times the MBC of the CK. The MBC:SOC ratios were 8.8%, 7.1%, 5.7% and 5.4% in DRM, RM, NM and WM, respectively. The ridge-furrow with plastic-mulching increased soil light fraction carbon (LFOC) in both years, averaging up to 1.04 g kg -1 at harvest. Underground plant biomass increased substantially in the mulching treatments, especially in DRM. Positive correlations were found between total biomass and LFOC, between MBC and LFOC, and between MBC and available phosphorus (AP), but a negative correlation between SOC and soil mineral nitrogen (MN). The carbon to phosphorus (C/P) ratio was highest in DRM among treatments, but the content of SOC, MN, and C/N ratio in DRM was lowest, suggesting that the DRM treatment strengthened the interactions between maize and soil, and that the increased content of LFOC with time provides a basis for increasing productivity in future years. In conclusion, the ridge-furrow and plastic-mulching technique brought about a challenge in maintaining soil fertility, but this technology provides a potential opportunity of substantially increasing crop yields in semiarid rainfed regions.
  • Authors:
    • Dauber, J.
    • Zimmermann, J.
    • Jones, M. B.
  • Source: GCB Bioenergy
  • Volume: 4
  • Issue: 4
  • Year: 2012
  • Summary: The use of biomass for energy production is considered a promising way to reduce net carbon emissions and mitigate climate change. However, land-use change to bioenergy crops can result in carbon emissions from soil and vegetation in amounts that could take decades to compensate. Perennial grasses such as Miscanthus offer a possible solution to this problem as measurements on experimental plots planted with Miscanthus have shown significant carbon sequestration in the soil. It can, however, be expected that sequestration potentials in commercial use might differ from those measured in experimental plots due to different farming practices and soil characteristics. For this study, Miscanthus plantations on 16 farms in SE Ireland as well as on-farm controls representing the former land-use (grassland and tillage) have been examined. The Miscanthus plantations were 2-3 years old. Soil organic carbon (SOC) content and a number of soil properties were measured and the amount of Miscanthus-derived carbon was determined using the 13C natural abundance method. On both former tillage fields and grasslands, although there were no significant differences in SOC contents between Miscanthus and control sites, it was shown that 2-3 years after Miscanthus establishment, 1.821.69 and 2.171.73 Mg ha -1 of the SOC under former-tilled and former grassland respectively were Miscanthus-derived. Mixed-effects models were used to link the total SOC concentrations and Miscanthus-derived carbon to the land-use parameters as well as to soil properties. It was shown that on control sites, pH had an effect on total SOC. In the case of Miscanthus-derived carbon, the initial SOC content, pH, former land-use and crop age had significant effects.
  • Authors:
    • Khan, M.
    • Said, G.
    • Inayatullah, A.
    • Khan, S.
    • Khalid, U.
    • Aziz-ur-Rehman
    • Khan, M.
  • Source: Philippine Agricultural Scientist
  • Volume: 95
  • Issue: 2
  • Year: 2012
  • Summary: Conservation tillage practices with an appropriate seed rate recover the declining wheat ( Triticum aestivum L.) yield and soil quality using conventional tillage in poorly drained silty clay soil (calcareous, hyperthermic and Typic Torrifluvents) in rice-wheat cropping system. Field experiments were conducted for 2 consecutive yr to study the impact of three tillage techniques [zero (ZT), reduced (RT) and conventional tillage (CT)] and four seed rates viz. 70, 100, 130 and 160 kg ha -1 on wheat yield, soil organic matter and total soil nitrogen in rice-wheat cropping system in northwestern Pakistan. Mean values for tillage revealed that conservation tillage (ZT and RT) resulted in higher spikes per m 2, biological yield, grain yield, soil organic matter and total soil nitrogen compared with CT. Mean values for seed rates displayed the highest yield and yield components at 130 kg ha -1 and showed the lowest values at 70 kg ha -1 seed rate. The results revealed that ZT/RT in combination with 130 kg ha -1 seed rate produced higher grain yield compared with CT in the first growing season. In contrast, CT in combination with 130 kg ha -1 seed rate gave the highest grain yield in the second growing season. The results emphasized the necessity of using 130 kg ha -1 seed rate in ZT for improving soil organic matter and total soil nitrogen, and sustaining wheat yield in poorly drained silty clay soil. However, in case of severe infestation with weeds or insect pests, CT in combination with 130 kg ha -1seed rate may be the best alternative.
  • Authors:
    • Calegari, A.
    • Santos, D.
    • Tiecher, T.
  • Source: Soil & Tillage Research
  • Volume: 124
  • Year: 2012
  • Summary: Organic phosphorus (P) is an important source of phosphate for plants both in natural environments and in cultivated soils. Growing plants with high P recycling capacity may increase the importance of organic forms in phosphate availability mainly in undisturbed soils. The aim of this study was to evaluate the effect of long period of cultivation of different winter species under different soil management systems in the distribution of soil organic P forms, in the P content stored into the soil microbial biomass (SMB) and in the acid phosphatase enzyme activity. The experiment was established in 1986 with six winter treatments (blue lupine, hairy vetch, oat, radish, wheat and fallow) implanted in a Rhodic Hapludox in southern Brazil, under no-tillage system (NT) and conventional tillage system (CT). The crops were cultivated with rational use of chemical phosphate fertilizer, according to plant needs and soil type maintaining high levels of soil organic carbon leading to P organic form accumulation. Growing crops during the winter period in highly weathered subtropical soil increases the importance of microbial interactions in the P cycle, especially in the NT, where a large amount of crop residues is annually added to the soil surface, increasing soil organic P level, P content stored into the SMB and acid phosphatase enzyme activity.
  • Authors:
    • Liu, W. Z.
    • Li, Y.
    • Zhu, H. H.
    • Coleman, K.
    • Wu, J. S.
    • Guo, S. L.
  • Source: Plant and Soil
  • Volume: 353
  • Issue: 1/2
  • Year: 2012
  • Summary: Aims: Concerns over food security and global climate change require an improved understanding of how to achieve optimal crop yields whilst minimizing net greenhouse gas emissions from agriculture. In the semi-arid Loess Plateau region of China, as elsewhere, fertilizer nitrogen (N) inputs are necessary to increase yields and improve local food security. Methods: In a dryland annual cropping system, we evaluated the effects of N fertilizers on crop yield, its long-term impact on soil organic carbon (SOC) concentrations and stock sizes, and the distribution of carbon (C) within various aggregate-size fractions. A current version (RothC) of the Rothamsted model for the turnover of organic C in soil was used to simulate changes in SOC. Five N application rates [0 (N0), 45 (N45), 90 (N90), 135 (N135), and 180 (N180) kg N ha -1] were applied to plots for 25 years (1984-2009) on a loam soil (Cumulic Haplustoll) at the Changwu State Key Agro-Ecological Experimental Station, Shaanxi, China. Results: Crop yield varied with year, but increased over time in the fertilized plots. Average annual grain yields were 1.15, 2.46, 3.11, 3.49, and 3.55 Mg ha -1 with the increasing N application rates, respectively. Long-term N fertilizer application increased significantly ( P=0.041) SOC concentrations and stocks in the 0-20 cm horizon. Each kilogram of fertilizer N applied increased SOC by 0.51 kg in the top soil from 1984 to 2009. Using RothC, the calculated annual inputs of plant C (in roots, stubble, root exudates, etc.) to the soil were 0.61, 0.74, 0.78, 0.86, and 0.97 Mg Cha -1 year -1 in N0, N45, N90, N135 and N180 treatments, respectively. The modeled turnover time of SOC (excluding inert organic C) in the continuous wheat cropping system was 26 years. The SOC accumulation rate was calculated to be 40.0, 48.0, 68.0, and 100.0 kg C ha -1 year -1 for the N45, N90, N135 and N180 treatments over 25 years, respectively. As aboveground biomass was removed, the increases in SOC stocks with higher N application are attributed to increased inputs of root biomass and root exudates. Increasing N application rates significantly improved C concentrations in the macroaggregate fractions (>1 mm). Conclusions: Applying N fertilizer is a sustainable practice, especially in carbon sequestration and crop productivity, for the semiarid Loess Plateau region.