• Authors:
    • Allen, B. L.
  • Source: Journal of Soil and Water Conservation
  • Volume: 67
  • Issue: 1
  • Year: 2012
  • Summary: Dryland corn (Zea mays L.) production in the northern Great Plains is limited by risk of crop failure due to drought conditions. Altering the row configuration and seeding rate have reduced the risk of yield loss elsewhere, but those areas typically receive greater precipitation than the annual average 300 to 350 mm (11.8 to 13.8 in) of the northern Great Plains. A study in 2007 and 2008 determined the impact of seeding rate and row configuration on dryland corn yield, yield quality and components, and precipitation use efficiency (PUE). Four sites in northeastern Montana were planted to corn (same variety) at four target rates (25,000, 37,500, 50,000 and 62,500 seeds ha−1 [10,000, 15,000, 20,000, and 25,000 seeds ac−1]) in conventional 0.61 m (24 in) spaced rows or in a skip-row configuration, with every third row skipped. Altering the row configuration had no impact on grain yield, harvest index, or grain PUE, but biomass yield and PUE were 12% and 15% greater for the skip-row configuration, compared to conventionally spaced corn. Interactions between row configuration and seeding rate were not significant (p < 0.05). Compared to row configuration, seeding rate had a greater impact on yield and showed an inverse and linear relationship, where biomass, grain yield, harvest index, and PUE for grain and biomass were 19%, 229%, 200%, 222%, and 22% greater for the lowest seeding rate, when compared to the highest. Overall results suggest that for areas with low rainfall, skip-row spacing provides a modest increase in biomass yield and that adjusting seeding rates to 27,000 seeds ha−1 (10,900 seeds ac−1) or lower will likely increase dryland corn biomass and especially grain yield, though caution is warranted in extending broadly the results of this limited dataset considering the variable nature of rainfall in semiarid environments.
  • Authors:
    • Antle, J. M.
    • Ogle, S. M.
  • Source: Climatic Change
  • Volume: 111
  • Issue: 3/4
  • Year: 2012
  • Summary: Previous research has demonstrated that soil carbon sequestration through adoption of conservation tillage can be economically profitable depending on the value of a carbon offset in a greenhouse gas (GHG) emissions market. However adoption of conservation tillage also influences two other potentially important factors, changes in soil N2O emissions and CO2 emissions attributed to changes in fuel use. In this article we evaluate the supply of GHG offsets associated with conservation tillage adoption for corn-soy-hay and wheat-pasture systems of the central United States, taking into account not only the amount of carbon sequestration but also the changes in soil N2O emission and CO2 emissions from fuel use in tillage operations. The changes in N2O emissions are derived from a meta-analysis of published studies, and changes in fuel use are based on USDA data. These are used to estimate changes in global warming potential (GWP) associated with adoption of no-till practices, and the changes in GWP are then used in an economic analysis of the potential supply of GHG offsets from the region. Simulation results demonstrate that taking N2O emissions into account could result in substantial underestimation of the potential for GHG mitigation in the central U.S. wheat pasture systems, and large over-estimation in the corn-soy-hay systems. Fuel use also has quantitatively important effects, although generally smaller than N2O. These findings suggest that it is important to incorporate these two effects in estimates of GHG offset potential from agricultural lands, as well as in the design of GHG offset contracts for more complete accounting of the effect that no-till adoption will have on greenhouse gas emissions.
  • Authors:
    • Gibson,Lance R.
    • Singer,Jeremy W.
    • Blaser,Brock C.
  • Source: Crop Science
  • Volume: 52
  • Issue: 1
  • Year: 2012
  • Summary: Frost-seeding red clover (Trifolium pratense L.) into winter cereals is an efficient establishment method, although performance under contrasting soil management practices remains unclear. Wheat and intercropped red clover productivity were evaluated in intensive tillage (IT), moderate tillage (MT), and no tillage (NT) with and without compost amendment in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.]-winter wheat (Triticum aestivum L.) and red clover rotation between 2005 and 2010. Wheat yields were not affected by tillage system and averaged 3.80 Mg ha(-1) but were 10% higher in compost amended soil compared to no compost. Red clover plant density and dry matter (DM) at cereal grain harvest averaged 127 plants m(-2) and 32 g m(-2) and were not affected by tillage or amendment treatments. Maximum wheat canopy light interception was attained in late May to early June and ranged from 84 to 91% and typically exceeded 77% light interception for at least 22 d. Red clover root DM increased on average 378% between wheat harvest and 40 d after harvest compared with a 64% average increase in red clover root length. Red clover shoot: root averaged 8.5 at wheat harvest compared with 11.2 40 d after wheat harvest. Producers using this wheat and red clover intercrop should expect no difference in wheat yield or red clover productivity when using IT, MT, or NT.
  • Authors:
    • Briedis, C.
    • Sa, J. C. de M.
    • Caires, E. F.
    • Navarro, J. de F.
    • Inagaki, T. M.
    • Boer, A.
    • Ferreira, A. de O.
    • Quadros Neto, C.
    • Canalli, L. B.
    • Santos, J. B. dos
  • Source: Soil Science Society of America Journal
  • Volume: 76
  • Issue: 1
  • Year: 2012
  • Summary: In a no-till system (NTS) on naturally acidic soils, surface liming is essential to neutralize soil acidity and increases crop productivity. As a result, the soil organic matter (SOM) pools of the soil surface layers may change, reflecting increased C inputs by crop residues. The objective of this study was to quantify changes in SOM pools and the rate of C sequestration that occur in response to surface liming in a long-term NTS experiment. The experiment was conducted in an Oxisol in southern Brazil. The treatments consisted of the application of 0 or 6 Mg ha -1 of dolomitic lime on the soil surface in 1993 and a reapplication of 0 or 3 Mg ha -1 of dolomitic lime in 2000 to plots with or without the previous lime application. Liming caused total organic C (TOC) accumulation, especially in the 0- to 2.5-cm layer. The amount of TOC stored in the 20-cm layer was 49.9, 52.9, 52.7, and 57.5 Mg ha -1 in the control, 6+0, 0+3, and 6+3 Mg ha -1 treatments, respectively. The levels of particulate organic C (POC) and mineral-associated organic C (MAOC) in the SOM were also enhanced by liming. The increase in POC was directly related ( R2=0.99, P=0.002) to the accumulation of C from crop residues, which was greater in the plots receiving lime treatment. There were positive correlations between TOC and C extractable with hot water, total polysaccharides, and labile polysaccharides. The correlation analysis also demonstrated that TOC was more tightly correlated with POC than with MAOC, indicating a greater influence of the labile fraction on the increase in TOC with surface liming.
  • Authors:
    • Caires, E. F.
    • Joris, H. A. W.
    • Churka, S.
    • Zardo Filho, R.
  • Source: Brazilian Archives of Biology and Technology
  • Volume: 55
  • Issue: 2
  • Year: 2012
  • Summary: The aim of this work was to study the effects of organic and mineral fertilizers at sowing (without fertilizers, organic poultry litter fertilizer on the surface and mineral NK+reactive natural phosphate from Arad and NK+triple superphosphate in the furrow) and topdressing (without fertilizers, organic poultry litter fertilization and urea) on chemical attributes of a no-till Oxisol and nutrition and yield of maize landrace ( Zea mays L.), Carioca variety in a field experiment. Results revealed that P content (Mehlich 1 and resin) was increased in the soil surface layer with organic poultry litter fertilizer on the surface at sowing. Mineral fertilizer in the sowing furrow could be replaced by organic fertilizer with poultry litter on the surface, but topdressing fertilization with urea resulted better N nutrition for the plants and higher grains yield than the organic poultry litter fertilization.
  • Authors:
    • Djigal, D.
    • Saj, S.
    • Rabary, B.
    • Blanchart, E.
    • Villenave, C.
  • Source: Soil & Tillage Research
  • Volume: 118
  • Year: 2012
  • Summary: Conservation agriculture (CA) is rapidly developing in Madagascar but little is known about its effects on local soil functioning. To assess some of those effects, we investigated the effects of three CA systems and two levels of fertilization on soil functioning using nematofauna as indicator. The systems consisted in (i) soybean (Glycine max L.)-maize (Zea mays L) rotation with mulch of residues, CA-R; (ii) bean (Phaseolus vulgaris L.)-soybean rotation with living mulch of Pennisetum clandestinum, CA-K; (iii) continuous maize with living mulch of Desmodium uncinatum, CA-D and were compared with soybean-maize under conventional tillage (CT) and natural fallow (NF). The fertilization levels consisted in ( i) farmyard manure, FYM; and (ii) farmyard manure + mineral fertilizers, FYM + NPK. Located in the Highlands of Madagascar, the experiment was setup in 1991 and andic Dystrustept soil had been sampled in 2005-2007. We measured nematode abundances and ecological indices as well as the abundance and biomass of soil macrofauna, soil water and organic C and N contents and plant yields. We hypothesized that (1) CA including maize in monoculture would lead to higher abundance of plant-parasitic nematodes; (2) both dead-residue mulch and inorganic fertilization would lead to a more basal nematode community structure; and (3) that the combination of system effects on soil nematode community would be able to forecast differential crop yields for the CA systems. Our results show that CA systems tested were able to support better/comparable maize and soybean yields compared with CT, provided that crop rotation is correctly managed. Supporting our first hypothesis, abundance of plant parasitic nematodes was (40-150 times) higher under maize monoculture. Abundance of soil nematofauna and trophic groups (excepted carnivores and omnivores) was stable during the three years. Inorganic fertilization increases carnivorous and omnivorous nematodes to 122% and 140%, respectively. Ecological indices showed that soil functioning of CA systems was intermediate between that NF and CT. CA systems were characterized by a highly structured soil food-web compared with CT. Yet, soil processes intensity revealed to be lower in CA with dead mulch compared with CA with living mulch, contrasting with our second hypothesis. The characterization of nematofauna discriminated well the different systems and supports our third hypothesis. Nematode structure and enrichment indices were significantly correlated to soil organic C and N content as well as grain yields. They proved to be powerful bio-indicators of soil functioning in the CA systems studied.
  • Authors:
    • Grace, P. R.
    • Ogle, S.
    • Paustian, K.
    • Antle, J.
    • Basso, B.
    • Aggarwal, P. K.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 146
  • Issue: 1
  • Year: 2012
  • Summary: Soil organic carbon sequestration rates over 20 years based on the Intergovernmental Panel for Climate Change (IPCC) methodology were combined with local economic data to determine the potential for soil C sequestration in wheat-based production systems on the Indo-Gangetic Plain (IGP). The C sequestration potential of rice-wheat systems of India on conversion to no-tillage is estimated to be 44.1 Mt C over 20 years. Implementing no-tillage practices in maize-wheat and cotton-wheat production systems would yield an additional 6.6 Mt C. This offset is equivalent to 9.6% of India's annual greenhouse gas emissions (519 Mt C) from all sectors (excluding land use change and forestry), or less than one percent per annum. The economic analysis was summarized as carbon supply curves expressing the total additional C accumulated over 20 year for a price per tonne of carbon sequestered ranging from zero to USD 200. At a carbon price of USD 25 Mg C -1, 3 Mt C (7% of the soil C sequestration potential) could be sequestered over 20 years through the implementation of no-till cropping practices in rice-wheat systems of the Indian States of the IGP, increasing to 7.3 Mt C (17% of the soil C sequestration potential) at USD 50 Mg C -1. Maximum levels of sequestration could be attained with carbon prices approaching USD 200 Mg C -1 for the States of Bihar and Punjab. At this carbon price, a total of 34.7 Mt C (79% of the estimated C sequestration potential) could be sequestered over 20 years across the rice-wheat region of India, with Uttar Pradesh contributing 13.9 Mt C.
  • Authors:
    • Gruber, S.
    • Pekrun, C.
    • Möhring, J.
    • Claupein, W.
  • Source: Soil & Tillage Research
  • Volume: 121
  • Year: 2012
  • Summary: The study provides information to more reliably estimate the value of conservation tillage in a temperate climate. Tillage effects on yield and weeds were evaluated in field experiments at two sites in SW Germany between 1999 and 2010. Tillage varied at site Ihinger Hof from mouldboard plough (P), chisel plough (CP), rototiller (RTT), varying P and CP (VAR), to no tillage (NT), partially combined with stubble tillage (S). Tillage at site Meiereihof was S/P, S/CP, and NT. Crop rotations included winter wheat (WW, Triticum aestivum), triticale (TR, Triticosecale), oat (OA, Avena sativa), silage maize (SM, Zea mays) and oilseed rape (OSR, Brassica napus) at Ihinger Hof, and winter wheat, spring barley (SB, Hordeum vulgare), silage maize, sugar beets (SBE. Beta vulgaris) and faba bean (FB, Vicia faba) at Meiereihof. At Ihinger Hof, tillage had an effect on yield (P > F = 0.0049), but no effects were found on crop emergence and crop density. Tillage effects on yield were consistent across crops though differences between crops appeared to exist. The yield of S/P, the standard tillage, was 8.5 (WW), 7.7 (TR), 4.7 (OA), 18.3 (SM) and 4.1 (OSR) t DM ha(-1) at Ihinger Hof, with yield under NT always significantly lower than S/P by 7.3% on average for all crops. At Meiereihof, yields ranged from 7.2 to 8.0 (WW), 3.3 to 4.2 (SB), 19.8 to 21.5 (SM) and 3.1 to 3.2 (FB) t DM ha(-1), and 61.3 to 67.6 FM ha(-1) for SBE. Yield was reduced by 4.5% from S/P to S/CP (P > F = 0.0516), and by about 10% from S/P to NT (P > F = 0.0009). Weed density ranged between 0.5 and 44 plants m(-2) at Ihinger Hof and was higher in treatments without stubble tillage and under non-inversion tillage, though significance differed for the different classes of weeds. NT led to weed infestation about 2-20 times higher than S/P. The interaction crop x treatment indicated that factors other than tillage influenced weed infestation. It is unlikely that weed infestation and reduced yield will be problems in temperate climates if soil disturbance through tillage is reduced. Non-inversion tillage can easily replace inversion tillage, and stubble tillage can be added to primary tillage if needed to reduce weeds. Since no specific tillage method was unequivocally superior to another one, any method well suited to specific regional and farm conditions can be adopted successfully.
  • Authors:
    • Hansen, N. C.
    • Allen, B. L.
    • Baumhardt, R. L.
    • Lyon, D. J.
  • Source: Field Crops Research
  • Volume: 132
  • Year: 2012
  • Summary: The Great Plains region of the United States is an area of widespread dryland crop production, with wheat being the dominant crop. Precipitation in the region ranges from 300 to 500 mm annually, with the majority of precipitation falling during hot summer months. The prevailing cropping system is a two-year rotation of wheat and summer fallow. The adoption of no-till practices has resulted in greater precipitation storage and use efficiency, which has led to greater cropping intensity, higher productivity, more diverse crop rotations, and improvements in soil properties. In Colorado, for example, a no-till rotation of winter wheat-maize-fallow increased total annualized grain yield by 75% compared to winter wheat-summer fallow. Soil erosion was reduced to just 25% of that from a conventional tillage wheat-summer fallow system. The primary challenge with reducing fallow frequency is the increase in yield variability and risk of crop failure. Improved approaches for choosing crop or fallow are being developed based on soil water content and forecasted weather. Development of alternative crops, crop rotations, and integrated livestock systems that are sustainable from both economic and ecological perspectives is an on-going effort. Other research is addressing adaptation of cropping practices to climate change and the potential for dryland biomass crop production for the developing biofuel industry.
  • Authors:
    • Barbarick, K. A.
    • Ippolito, J. A.
    • McDaniel, J.
    • Hansen, N. C.
    • Peterson, G. A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 150
  • Year: 2012
  • Summary: Dryland agroecosystems are generally ideal environments for recycling biosolids. However, what is the efficacy of biosolids addition to a no-till dryland management agroecosystem? From 2000 to 2010, we studied application of biosolids from the Littleton/Englewood, CO Wastewater Treatment Plant versus commercial N fertilizer in dryland no-till wheat ( Triticum aestivum, L.)-fallow (WF) and wheat-corn ( Zea mays, L.)-fallow (WCF) rotations at a site approximately 40 km east of Byers, CO. We tested if biosolids would produce the same yields and grain P, Zn, and Ba concentrations as an equivalent rate of N fertilizer, that biosolids-borne P, Zn, and Ba would not migrate below the 10 cm soil depth, and that biosolids application would result in the same quantity of residual NO 3-N as the equivalent N fertilizer rate. Biosolids and N fertilizer produced similar wheat and corn yields; but, biosolids application resulted in smaller wheat grain Ba due to the soil formation of BaSO 4. Biosolids application produced greater NO 3-N concentrations than N fertilizer in the 30-60 and 60-90 cm depths for the WF rotation and all but the 5-10 and 120-150 cm depths for the WCF rotation. We concluded that biosolids application in a no-till managed dryland agroecosystem is an efficacious method of recycling this nutrient source.