• Authors:
    • Blanco-Canqui, H.
  • Source: Soil Use and Management
  • Volume: 27
  • Issue: 1
  • Year: 2011
  • Summary: Soil water repellency (SWR) is an intrinsic and dynamic soil property that can influence soil hydrology and crop production. Although several land use systems have been shown to induce water repellency in soil, the specific effects of no-till cropping on SWR are poorly understood. This article reviews the impacts of no-till on SWR and identifies research needs. No-till cropping generally induces 1.5 to 40 times more SWR than conventional tillage, depending on soil type. This may result from near-surface accumulation of hydrophobic organic C compounds derived from crop residues, microbial activity and reduced soil disturbance. While large SWR may have adverse impacts on soil hydrology and crop production, the level of SWR under no-till relative to conventional tillage may contribute to aggregate stabilization and intra-aggregate C sequestration. More research is needed to discern the extent and relevance of no-till induced SWR. This includes: (1) further assessment of SWR under different tillage systems across a wide range of soil textures and climates, (2) comparison of the various methods for measuring SWR over a range of water contents, (3) inclusion of SWR in routine soil analysis and its use as a parameter to evaluate management impacts, (4) assessment of the temporal and spatial changes in SWR under field conditions, (5) further assessment of the impacts of the small differences in SWR between no-till and conventionally tilled soils on crop production, soil hydrology and soil C sequestration, and (6) development of models to predict SWR for different tillage systems and soils.
  • Authors:
    • Janzen, H. H.
    • Ellert, B. H.
    • McKenzie, R. H.
    • Bremer, E.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 4
  • Year: 2011
  • Summary: Agroecosystems provide a range of benefits that are strongly influenced by cropping practice. Crop productivity and C, N, and greenhouse gas (GHG) balances were evaluated in an 18-yr cropping system study on an Aridic Haplustoll in the northern Great Plains. Application of synthetic fertilizers consistently increased crop yield and soil organic carbon (SOC), with greatest impact in perennial grass and continuous wheat ( Triticum aestivum L.) rotations and least impact in rotations with fallow or annual legumes. Based on N balance, N inputs other than fertilizer were 16 to 30 kg N ha -1 yr -1 in rotations without legumes and 62 kg N ha -1 yr -1 in a legume-wheat (LW) rotation, while losses of synthetic fertilizer N were 32% in annual crop rotations and 3% in perennial grass. Due to large gains in SOC, perennial grass reduced atmospheric GHG by 20 to 29 Mg CO 2 equivalent (eq.) ha -1 during the 18 yr of this study. For annual crop rotations, seed yield ranged from 1.2 to 2.5 Mg ha -1 yr -1, protein yield from 0.20 to 0.41 Mg ha -1 yr -1, and GHG intensity from 0 to 0.5 Mg CO 2 eq. Mg -1 seed. Fertilized continuous wheat had the highest crop productivity and lowest net GHG intensity, while an annual LW rotation had the highest protein productivity and among the lowest GHG intensities (0.2 Mg CO 2 eq. Mg -1 seed). Further evaluation at broader temporal and spatial scales is necessary to account for future changes in SOC and differences in use of crop products.
  • Authors:
    • VandenBygaart, A. J.
    • Zentner, R. P.
    • Lemke, R.
    • May, W. E.
    • Holzapfel, C. B.
    • Campbell, C. A.
    • Lafond, G. P.
  • Source: Canadian Journal of Plant Science
  • Volume: 91
  • Issue: 3
  • Year: 2011
  • Summary: We analyzed the agronomic data from a 50-yr crop rotation experiment being conducted on a fine-textured, thin Black Chernozem at Indian Head, Saskatchewan in Canada. Our objective was to determine how a change from conventional-till to no-till, together with an increase in N fertilizer rates recommended by the Saskatchewan Soil Testing Laboratory has affected wheat yields and N and P balance in the systems over the past 20 yr. The treatments assessed were fertilized (N-P) and unfertilized fallow-wheat ( Triticum aestivum L.) (F-W), F-W-W, and continuous wheat (ContW), and unfertilized legume green manure (LGM)-W-W and F-W-W-brome ( Bromus inermis Leyss.)/alfalfa ( Medicago sativa L.) hay (H)-H-H. On average, N applied to wheat grown on fallow was 6 kg ha -1 yr -1 from 1957 to 1989 and 57 kg ha -1 yr -1 from 1990 to 2007; for wheat grown on stubble, the N rates were 21 kg ha -1 yr -1 from 1957 to 1977 and 85 kg ha -1 yr -1 thereafter. Crops received P at 10 kg ha -1 yr -1. On average, fertilizer increased wheat yield of fallow-wheat by 31%; the hay system increased fallow-wheat yield by 26% compared with unfertilized fallow-wheat in F-W-W, and the LGM system increased it by 14%. Effects were greater on stubble crop than on fallow crop, with fertilizer increasing the yield of wheat grown on stubble in the monoculture system by 114%, the hay system increasing it by 83% and the LGM system increasing it by 37%. The legume-containing rotations increased yields by increasing the N supplying capacity of the soil with the hay system being more effective than the LGM because legumes occurred more frequently in the hay rotation (3 in 6 yr vs. 2 in 6 yr). The benefit of the legume-containing systems on wheat yield may have been restricted because this unfertilized system steadily depleted available soil P. Average annualized wheat production in F-W, F-W-W and ContW rotations was unaffected by cropping frequency for the unfertilized systems, but it was directly proportional to cropping frequency for the fertilized systems. Annualized wheat production for the LGM-W-W rotation was 18% greater than for unfertilized F-W-W, but 41% less than for the fertilized F-W-W. Annualized wheat production in the hay-containing rotation was 32% less than in the unfertilized F-W-W rotation because of the less frequent presence of wheat in the hay system. Greater rates of N fertilizer in the later years increased yields and grain N content; this resulted in less residual NO 3-N in the soil compared with previous years with lower fertilizer N. Thus, we expect there will be less likelihood of NO 3 leaching under fallow-containing systems under no-till when updated fertilizer recommendations are used compared with previous results under conventional tillage with lower rates of N applications.
  • 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:
    • 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:
    • Daigh, A. L.
  • Source: Soil Survey Horizons
  • Volume: 52
  • Issue: 2
  • Year: 2011
  • Summary: Bioenergy cropping systems will supply 16 billion gallons of cellulosic ethanol by the year 2022 in an attempt to reduce U.S. dependence on gasoline. To obtain long-term energy security, bioenergy systems will need to be sustainable, especially with regard to soil. Corn stover, as a bioenergy feedstock, is of great interest due to its immediate availability for harvest with minimal change to current corn-grain cropping systems. However, traditional row crop agriculture of the United States Corn Belt has reduced soil organic matter contents, an indicator of soil quality, by as much as 40 to 60% over the last 150 yr. The harvest of corn stover will directly remove a portion of the soil organic matter input, thus further reducing soil organic matter contents. The reduction in soil organic matter contents produce direct and indirect consequences unfavorable to soil quality and productivity. Therefore, the harvest of corn stover as a long-term bioenergy feedstock is detrimental to soil, impacting soil structure and stability, erodibility, A horizon depth, and physicochemical properties. Perennial biofuel systems, in contrast, have the potential to add soil organic matter to the soil, thus offering long-term enhancement of soil quality, productivity, and formation.
  • 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:
    • Slepetiene, A.
    • Liaudanskiene, I.
    • Kadziene, G.
    • Deveikyte, I.
    • Vaideliene, A.
    • Feiziene, D.
    • Feiza, V.
  • Source: Journal of Environmental Quality
  • Volume: 40
  • Issue: 6
  • Year: 2011
  • Summary: The importance of agricultural practices to greenhouse gas mitigation is examined worldwide. However, there is no consensus on soil organic carbon (SOC) content and CO 2 emissions as affected by soil management practices and their relationships with soil texture. No-till (NT) agriculture often results in soil C gain, though, not always. Soil net CO 2 exchange rate (NCER) and environmental factors (SOC, soil temperature [T soil], and water content [W soil]), as affected by soil type (loam and sandy loam), tillage (conventional, reduced, and NT), and fertilization, were quantified in long-term field experiments in Lithuania. Soil tillage and fertilization affected total CO 2 flux (heterotrophic and autotrophic) through effect on soil SOC sequestration, water, and temperature regime. After 11 yr of different tillage and fertilization management, SOC content was 23% more in loam than in sandy loam. Long-term NT contributed to 7 to 27% more SOC sequestration on loam and to 29 to 33% more on sandy loam compared with reduced tillage (RT) or conventional tillage (CT). Soil water content in loam was 7% more than in sandy loam. Soil gravimetric water content, averaged across measurement dates and fertilization treatments, was significantly less in NT than CT and RT in both soils. Soil organic carbon content and water storage capacity of the loam and sandy loam soils exerted different influences on NCER. The NCER from the sandy loam soil was 13% greater than that from the loam. In addition, NCER was 4 to 9% less with NT than with CT and RT systems on both loam and sandy loam soils. Application of mineral NPK fertilizers promoted significantly greater NCER from loam but suppressed NCER by 15% from sandy loam.
  • Authors:
    • Feng, G.
    • Sharratt, B.
    • Young, F.
  • Source: Journal of Soil and Water Conservation
  • Volume: 66
  • Issue: 4
  • Year: 2011
  • Summary: In the low precipitation zone (<0.3 m [11.8 in] annual precipitation) of the Inland Pacific Northwest, no-tillage continuous spring cereal and no-tillage spring cereal-chemical fallow rotations are being examined as alternatives to the traditional winter wheat-summer fallow rotation for soil conservation. There is limited information, however, regarding the long-term effects of no-tillage cropping systems on soil hydraulic properties in this semiarid region. The objective of this study was therefore to characterize infiltration, water retention, saturated hydraulic conductivity and bulk density of a silt loam that had been subject to various tillage and crop rotations in east-central Washington. Treatments examined included no-tillage spring barley-spring wheat (NTSB-SW), no-tillage spring wheat-chemical fallow (NTSW-ChF), and traditional winter wheat-summer fallow (WW-SF). Soil properties were measured in spring and late summer 2006 due to the vulnerability of the soil to rapidly dry and erode during these seasons. Saturated hydraulic conductivity was determined by the falling-head method, infiltration was measured using a double-ring infiltrometer, and water retention characteristics was assessed by examining the temporal variation of in situ soil water content. NTSB-SW resulted in higher infiltration and saturated hydraulic conductivity, lower bulk density, and larger and/or more continuous pores in the upper soil profile (<0.1 in [<3.9 in] depth) than WW-SF and NTSW-ChE Infiltration and saturated hydraulic conductivity were lower for chemical fallow than for traditional fallow in spring whereas hydraulic conductivity was lower for summer fallow than chemical fallow in late summer. Soil hydrologic properties appeared more favorable for no-tillage continuous spring cereal rotations. These results arc useful for soil and water management and conservation planning in the low precipitation zone of the Inland Pacific Northwest.
  • Authors:
    • Fernandez, M. R.
    • Ulrich, D.
    • Brandt, S. A.
    • Zentner, R. P.
    • Wang, H.
    • Thomas, A. G.
    • Olfert, O.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 3
  • Year: 2011
  • Summary: The impact of cropping system management on root and crown rot of spring wheat ( Triticum aestivum L.) was examined on a Dark Brown Chernozem (Typic Boroll) soil in the Canadian Prairies. This systems approach tried to reflect the most common practices of organic and conventional producers in this region. The study consisted of a factorial combination of three input levels (high, with tillage, fertilizer and pesticides; reduced [RED], with conservation tillage, targeted fertilizer and weed control; and organic [ORG] with tillage and N-fixing legumes); and three levels of cropping diversity (low diversity with wheat and summerfallow or legume green manure fallow; diversified using annual grain crops; and diversified using annual grain crops and perennial forages). All rotations were 6 yr long. Subcrown internodes and crowns/lower culms of wheat plants were scored for discoloration, and fungi in discolored tissue were identified and quantified. Overall, input level had a greater impact on disease levels and fungal frequency than cropping diversity. Discoloration severity was lowest in the RED systems, which was attributed to lower percentage isolation of Cochliobolus sativus, the most common pathogen. Fusarium species varied with input level. The pathogens F. avenaceum and F. culmorum were most associated with RED and/or least associated with ORG systems, whereas the weak pathogen/saprophyte F. equiseti was most associated with ORG systems. Thus, ORG management helped to reduce populations of F. avenaceum and F. culmorum, two of the most important Fusarium pathogens in the Canadian Prairies.