• 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:
    • 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.
  • Authors:
    • Ferreira, R.
    • Galvao, R.
    • Miranda Junior, E.
    • Araujo Neto, S.
    • Negreiros, J.
    • Parmejiani, R.
  • Source: Horticultura Brasileira
  • Volume: 29
  • Issue: 3
  • Year: 2011
  • Summary: The use of volunteer plants and live coverage of peanut ( Arachis pintoi) was evaluated, associating the application of organic compost in organic production of radish in no-till. The experiment was carried out at Federal University of Acre, in Rio Branco, Acre State, Brazil. A randomized complete block design with a split plot arrangement (4*3) and four replications was used. The plots consisted of the no-tillage systems with live coverage of peanut, with live coverage of spontaneous plants (weeds), with mulching of spontaneous plants, and conventional soil tillage with no-mulching soil. The subplots were composed of the doses of organic compost of 5, 10 and 15 t ha -1 in dry basis. The no-tillage with straw weed mulch had similar performance to the conventional soil tillage, both superior to the crop on the no-tillage with live mulch. The productivity of the radish cv. Cometa, was not affected by increasing doses of organic compost, being possible to apply only 5 t ha -1, whereas in the conventional tillage, the increasing productivity was higher compared to the direct planting only in the higher dose of compost (15 t ha -1).
  • Authors:
    • Franzluebbers, A. J.
    • Causarano, H. J.
    • Norfleet, M. L.
  • Source: Plant and Soil
  • Volume: 338
  • Issue: 1-2
  • Year: 2011
  • Summary: Prediction of soil organic C sequestration with adoption of various conservation agricultural management approaches is needed to meet the emerging market for environmental services provided by agricultural land stewardship. The soil conditioning index (SCI) is a relatively simple model used by the USDA-Natural Resources Conservation Service to predict qualitative changes in soil organic matter. Our objective was to develop a quantitative relationship between soil organic C derived from published field studies in the southeastern USA and SCI scores predicted from matching management conditions. We found that soil organic C sequestration (at 20 +/- 5 cm depth) could be reliably related to SCI across a diversity of studies in the region using the regression slope: 1.65 Mg C ha(-1) SCI(-1) [which translated into a rate of 0.25 +/- 0.04 Mg C ha(-1) yr(-1) SCI(-1) (mean +/- standard error of 31 slope estimates)]. The calibration of soil organic C on SCI scores will allow SCI to become a quantitative tool for natural resource professionals to predict soil organic C sequestration for farmers wanting to adopt conservation practices.
  • Authors:
    • Li, Mei
    • Gao, XingXiang
    • Guo, Xiao
    • Sun, TingLin
    • Zhao, Wei
    • Gao, ZongJun
  • Source: Acta Prataculturae Sinica
  • Volume: 20
  • Issue: 1
  • Year: 2011
  • Summary: The effects of rotary tillage with no stubble (RT), rotary tillage with straw incorporation (RTS), no-till without stubble (NT), no-till with 6 000 kg/ha (NTS 6000), and no-till with 3 000 kg/ha (NTS 3000), on weed communities structure and species diversity was studied in field experiments using a community ecology method. Compared with RT, the NT, NTS 3000, and NTS 6000 treatments increased perennial weed species, but there was no significant difference in the species richness. NT, NTS 3000 and NTS 6000 significantly reduced the summed dominance ratio (SDR) of Lithospermum arvense, but increased the SDR of Capsella bursa-pastoris. RTS significantly reduced the SDR of L. arvense, but increased the SDR of Descurainia sophia. The species diversity of weed communities varied significantly between different tillage systems. The Bray-Curtis index and hierarchical cluster analysis classified the weed communities of different tillage systems into two categories: Category I (NT, NTS 6000 and NTS 3000) where no-till was implemented, and category II (RTS and RT) where rotary tillage was implemented. The species richness of category I was a little larger than that of category II, but the species diversity and community evenness were much larger than those of category II. However, the community dominance of category I was significantly smaller than that of category II.
  • Authors:
    • Garland, G. M.
    • Suddick, E.
    • Burger, M.
    • Horwath, W. R.
    • Six, J.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 144
  • Issue: 1
  • Year: 2011
  • Summary: Knowing underlying practices for current greenhouse gas (GHG) emissions is a necessary precursor for developing best management practices aimed at reducing N2O emissions. The effect of no-till management on nitrous oxide (N2O), a potent greenhouse gas, remains largely unclear, especially in perennial agroecosystems. The objective of this study was to compare direct N2O emissions associated with management events in a cover-cropped Mediterranean vineyard under conventional tillage (CT) versus no-till (NT) practices. This study took place in a wine grape vineyard over one full growing season, with a focus on the seven to ten days following vineyard floor management and precipitation events. Cumulative N2O emissions in the NT system were greater under both the vine and the tractor row compared to CT, with 0.15 ± 0.026 kg N2O–N ha−1 growing season−1 emitted from the CT vine compared to 0.22 ± 0.032 kg N2O–N ha−1 growing season−1 emitted from the NT vine and 0.13 ± 0.048 kg N2O–N ha−1growing season−1 emitted from the CT row compared to 0.19 ± 0.019 kg N2O–N ha−1 growing season−1 from the NT row. Yet these variations were not significant, indicating no differences in seasonal N2O emissions following conversion from CT to NT compared to long-term CT management. Individual management events such as fertilization and cover cropping, however, had a major impact on seasonal emissions, indicating that management events play a critical role in N2O emission patterns.
  • Authors:
    • Rickman, R. W.
    • Liang, Y.
    • Albrecht, S. L.
    • Machado, S.
    • Kang, S.
    • Gollany, H. T.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 1
  • Year: 2011
  • Summary: Long-term field experiments (LTE) are ideal for predicting the influence of agricultural management on soil organic carbon (SOC) dynamics and examining biofuel crop residue removal policy questions. Our objectives were (i) to simulate SOC dynamics in LTE soils under various climates, crop rotations, fertilizer or organic amendments, and crop residue managements using the CQESTR model and (ii) to predict the potential of no-tillage (NT) management to maintain SOC stocks while removing crop residue. Classical LTEs at Champaign, IL (1876), Columbia, MO (1888), Lethbridge, AB (1911), Breton, AB (1930), and Pendleton, OR (1931) were selected for their documented history of management practice and periodic soil organic matter (SOM) measurements. Management practices ranged from monoculture to 2- or 3-yr crop rotations, manure, no fertilizer or fertilizer additions, and crop residue returned, burned, or harvested. Measured and CQESTR predicted SOC stocks under diverse agronomic practices, mean annual temperature (2.1-19 degrees C), precipitation (402-973 mm), and SOC (5.89-33.58 g SOC kg(-1)) at the LTE sites were significantly related (r(2) = 0.94, n = 186, P < 0.0001) with a slope not significantly different than 1. The simulation results indicated that the quantities of crop residue that can be sustainably harvested without jeopardizing SOC stocks were influenced by initial SOC stocks, crop rotation intensity, tillage practices, crop yield, and climate. Manure or a cover crop/intensified crop rotation under NT are options to mitigate loss of crop residue C, as using fertilizer alone is insufficient to overcome residue removal impact on SOC stocks.
  • Authors:
    • Gruber, S.
    • Möhring, J.
    • Claupein, W.
  • Source: Soil & Tillage Research
  • Volume: 115
  • Year: 2011
  • Summary: Ten years of a long-term field experiment using different strategies of conventional and conservation tillage in SW Germany were evaluated for soil mineral nitrogen (SMN) and soil moisture content. Treatments analysed were combinations of stubble tillage (S) or no stubble tillage with primary tillage P: mouldboard plough, CP: chisel plough, RTT: rototiller, NT: no-till, and VAR: alternating SIP or S/CP. Best management practices were used for crop rotation, fertilisation and plant protection. CP, VAR and NT resulted in 18.7-19.0% gravimetric water content in spring. Partially significantly lower water content was observed in spring under S/P and CP with 18.2%; P and S/RTT resulted in 18.5%. Autumn soil moisture ranged from 15.3 to 15.8% and did not significantly differ between the treatments. Interactions between treatment and depth were not significant. There was no clear trend for spring soil moisture. No treatment showed a particular response to dry or wet season. Total SMN ranged between 8 and 49 kg ha(-1) in spring and 5-26 kg ha(-1) in autumn; significant effects of the treatments or interactions of treatment x depth did not occur. The effect of the season was most relevant for the amount of SMN, probably as a result of different conditions for mineralisation. Downward movement of nitrogen in spring was low in all treatments if catch crops were grown in the previous autumn. Overall, different soil tillage methods had little effect on soil moisture and soil SMN under temperate conditions. Seriously adverse effects of any tillage treatment in terms of nitrate leaching or reduced mineralisation seem unlikely. Similarly, the tillage systems did not exhibit obvious advantages or disadvantages in terms of soil water content. An exception may have been the higher water content in autumn in 0-30 cm under high soil disturbance which provided more suitable conditions for germination of the following crop. The decision of whether or not to adopt conservation tillage in temperate climates seems not to be primarily dependent on soil moisture and nitrogen mineralisation or on nitrogen leaching.
  • Authors:
    • Gürsoy, S. L.
    • Sessiz, A.
    • Kiliç, H.
    • Bayram, N.
  • Source: Archives of Agronomy and Soil Science
  • Volume: 57
  • Issue: 4
  • Year: 2011
  • Summary: Soil properties are very important for plant growth and soil conservation. Although soil properties can be influenced by agricultural production systems, this influence has seldom been studied in the semi-arid South East Anatolia region of Turkey. Thus, a three-year experiment was carried out to evaluate the effect of tillage and residue management systems in wheat ( Triticum durum L.) agriculture following cotton ( Gossypium hirsutum L.) on soil properties. A strip plot design with three replications was used, in which two residue management treatments were collecting cotton stalk (SA) and chopping cotton stalk (SB), and six tillage treatments were conventional tillage-I (CT-I), conventional tillage-II (CT-II), vertical tillage (VT), reduced tillage-I (RT-I), reduced tillage-II (RT-II), no-till ridge planting (RP). While there was no difference at 10-20 and 20-30 cm, the penetration resistance was the lowest for CT-I (1.62 MPa) at 0-10 cm. Although tillage treatments had no significant effect on the soil bulk density at 0-10 and 20-30 cm, the lowest bulk density were obtained in RT-II (1.19 g cm -3) at 10-20 cm. Tillage and residue management treatments did not influence the soil organic matter content and pH.
  • Authors:
    • Hammond, R.
  • Source: IOBC/WPRS Bulletin
  • Volume: 64
  • Year: 2011
  • Summary: Slugs are often problems in field crops grown using conservation tillage practices in the eastern United States, as well as certain locations in the Midwest and the southern USA, as well as in Canada. Although most concern has been on corn and soybean, reports of problems from dry beans, cotton, oil-seed rape, sunflowers, winter wheat, and fall planted alfalfa are often received. Although most problems are in fields located in the original forested areas of eastern and southern USA, reports are also being received from the Great Plains' grass lands of slug issues in irrigated no-till fields. Overall, slug problems have increased in geographical area as growers in the USA and Canada have adopted conservation tillage practices. As in other areas of the world, determining new methods of slug control is of utmost importance in order to allow growers to continue using conservation tillage practices. In areas that are new to slugs, a primary concern is educating growers on IPM approaches to slug management.