• Authors:
    • Schillinger, W.
    • Wuest, S.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 4
  • Year: 2011
  • Summary: Farmers in the low-precipitation (<300 mm annual) region of the Inland Pacific Northwest of the USA practice summer fallow to produce winter wheat ( Triticum aestivum L.) in a 2-yr rotation. No-till fallow (NTF) is ideal for wind erosion control but is not widely practiced because of seed-zone soil drying during the summer, whereas adequate seed-zone water for germination and emergence of deep-sown winter wheat can generally be retained with tilled fallow (TF). Successful establishment of winter wheat from late August- early September planting is critical for optimum grain yield potential. A 6-yr field study was conducted to determine if accumulations of surface residue under long-term NTF might eventually be enough to substitute for TF in conserving seed-zone water over summer. Averaged over the 6 yr, residue rates of 1500, 6000, and 10 500 kg ha -1 (1*, 4*, and 7* rates, respectively) on NTF produced incrementally greater seed-zone water but were not capable of conserving as much as TF. Total root zone (0-180 cm) over-summer water loss was greatest in the 1 * NTF whereas there were no significant differences in the 4* and 7* NTF versus TF. Average precipitation storage efficiency ranged from 33% for 1* NTF to 40% for TF. We conclude that for the low-precipitation winter wheat-summer fallow region of the Inland Pacific Northwest: (i) Cumulative water loss during the summer from NTF generally exceeds that of TF; (ii) there is more extensive and deeper over-summer drying of the seed-zone layer with NTF than with TF; (iii) increased quantities of surface residue in NTF slow the rate of evaporative loss from late-summer rains, and (iv) large quantities of surface residue from April through August will marginally enhance total-profile and seed-zone water in NTF, but will not retain adequate seed-zone water for early establishment of winter wheat except sometimes during years of exceptionally high precipitation or when substantial rain occurs in mid-to-late August.
  • Authors:
    • Gurjeet, G.
    • Malik, R.
    • Ashok, Y.
    • Kamboj, B.
    • Yadav, D.
  • Source: Environment and Ecology
  • Volume: 29
  • Issue: 4
  • Year: 2011
  • Summary: Two field experiments were conducted during kharif of 2009, to optimize ground cover by green manure cover crops before taking no-till direct seeded basmati rice and mechanical transplanted coarse grain rice. The treatments included three cover crops ( Sesbania, mungbean and cowpea) with two seed rates (X and 2X) along with check (without cover crop) under no-till after wheat harvest. The X seed rates for Sesbania, mungbean and cowpea were 30, 20 and 50 kg/ha, respectively. Farmers' field trails on the issue in question were also conducted at three locations. Weed infestation until cover crops were knocked down, was significantly reduced due to growing of cover crops as compared to plots where no cover crop was included. Minimum density and dry weight of weeds was recorded with Sesbania at 60 kg/ha seed rate which was superior to all other treatments. This could be due to ample ground cover and heavy biomass production by Sesbania. In general biomass production among green manure cover crops was followed the sequence of Sesbania > cowpea > mungbean. Due to lower cost of seed, Sesbania at 60 kg/ha was realized more economical than other cover crops. Infestation of Echinochloa sp. in rice was lowest in the plots where Sesbania was taken as preceding cover crop and it was superior to other two cover crops. There was no infestation of sedges in rice in the plots where cover crops were grown but there was infestation of sedges in check plots. There was no significant impact of different cover crops on the yield and yield attributed of rice; however, to attain higher returns, inclusion of green manure cover crops on long-term basis could be more meaningful.
  • Authors:
    • Laboski, C.
    • Andraski, T.
    • Yague, M.
  • Source: Journal of Environmental Quality
  • Volume: 40
  • Issue: 6
  • Year: 2011
  • Summary: Greater demand for corn ( Zea mays L.) stover for bioenergy use may lead to increased corn production acreage with minimal surface residue cover, resulting in greater risk for soil erosion and phosphorus (P) losses in runoff. A rainfall simulation study was conducted to determine the effects of spring-applied dairy cow ( Bos taurus) manure (none, in-barn composted, and exterior walled-enclosure pit) with >200 g kg -1 organic solids content following fall corn biomass removal with and without incorporation (chisel plow [CP] and no-till [NT]) on sediment and P in runoff. Runoff was collected from a 0.83-m 2 area for 60 min following the onset of rainfall simulation (76 mm h -1), once in spring and once in fall. Runoff dissolved reactive P (DRP) and dissolved organic P (DOP) concentrations were positively correlated with manure P rate and were higher in NT compared with CP. Conversely, sediment and particulate P (PP) concentrations in runoff were inversely correlated with manure P rate (and manure solids) and were higher in CP compared with NT. Runoff volume where no manure was applied was higher in NT than in CP in spring but similar in fall. The addition of manure reduced runoff volumes by an average of 82% in NT and 42% in CP over spring and fall. Results from this study indicate that surface application of dairy manure with relatively high solids content may reduce sediment and PP losses in runoff without increasing the risk of increased DRP and DOP losses in the year of application where corn biomass is harvested.
  • Authors:
    • Du, R.
    • Cai, S.
    • Geng, D.
    • Song, J.
    • Yang, Z.
  • Source: International Agricultural Engineering Journal
  • Volume: 20
  • Issue: 2
  • Year: 2011
  • Summary: Based on the agronomic characteristics of yearly maize-wheat rotation in Huanghuaihai Plain, a new-concept no-till planter, named 2BMDF-8 no-till wheat-maize planter, has been developed by Shandong University of Technology to solve an extremely important problem, such as standing maize stubble in one pass in two-crop rotation areas of Shandong Province in China. The combine anti-blocking device that is composed of power chopping axle and the planting unit of double-disc opener was designed. The test results of field performance showed that the machine could accomplish many working procedures, such as stubble chopping, furrow opening, seeds and fertilizer placement etc, in one pass, so the operation cost could be decreased by about 30%. The machine worked well for planting wheat into fields with standing maize stubble and maize stubble shattered. The powered chopping axle resolved the anti-blockage problem that ahead of shank the double-disc opener unit reduced the blockage between planting units. Meanwhile the variations in seed depth reduced to 18.8% and 19.3% respectively. Therefore, this machine will be a good solution to no-till wheat-maize planting in two crop rotation areas.
  • Authors:
    • Lemke, R.
    • Frick, B.
    • Nagy, C. N.
    • Campbell, C. A.
    • Ulrich, D.
    • Thomas, A. G.
    • Brandt, S. A.
    • Basnyat, P.
    • Zentner, R. P.
    • Malhi, S. S.
    • Olfert, O. O.
    • Fernandez, M. R.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 26
  • Issue: 3
  • Year: 2011
  • Summary: Producers in the semi-arid Dark Brown Chernozemic (Typic Boroll) soil zone of the Canadian Prairie are contemplating changes to land-use practices, moving away from conventional high-input production systems that specialize in one or two annual grain crops to more diversified and extended cropping systems that use reduced-input and organic management practices. This study examined the economic merits of nine cropping systems, consisting of a factorial combination of three input management methods and three levels of cropping diversity. It was conducted over the 1996-2007 period on a loam soil at Scott, Saskatchewan. The input treatments were: (1) high input (HIGH), which used conventional tillage and full recommended rates of fertilizers and pesticides 'as required'; (2) reduced input (RED), which used conservation tillage and integrated weed and nutrient management practices in an effort to lower requirements for fuel, fertilizers and pesticides; and (3) organic input (ORG), which used tillage, non-chemical pest control, higher seeding rates, delayed seeding and legume crops to replenish soil nutrients. The crop diversity treatments included: (1) a fallow-based rotation with low crop diversity (LOW); (2) a diversified annual rotation of cereal, oilseed and pulse grains (DAG); and (3) a diversified rotation using annual grains and perennial forages (DAP). All crop rotations were 6 years in length. At the 2007 input costs and prices, average net returns and 12-year net present values were higher for organic than for non-organic treatments, with the ORG input/LOW crop diversity system being the most profitable (net returns=$234 ha -1 yr -1 and net present value=$1953 ha -1). Net returns averaged about 10% less for ORG/DAG compared to the most profitable system, and about 22% less for HIGH/DAG and RED/DAG (the best non-organic systems). The DAP treatments that included forage were not economically competitive with the other treatments, often producing economic losses. The relative profitability of the organic treatments was highly dependent on the existence of organic price premiums. When price premiums for organic crops were reduced to less than 70% of the 2007 levels, the organic treatments were less profitable than the comparable non-organic treatments. The organic treatments also experienced significantly lower (and often negative) net returns compared to the non-organic treatments during completion of the 3-year organic certification period. We estimated that it required 5-7 years after completion of certification for the organic treatments to break even with the comparable non-organic treatments. Thereafter the organic treatments produced consistently higher net earnings. Production costs averaged 16% lower with ORG management compared to the HIGH-input treatments, but we found little difference in total costs between the respective HIGH- and RED-input treatments. The organic treatments also displayed lower income variability than the non-organic treatments, with the ORG/LOW system being preferred by risk-averse producers, who do not subscribe to all-risk crop insurance, and with the ORG/LOW and ORG/DAG systems preferred by low and medium risk-averse producers when having the added financial protection from the Canada/Saskatchewan all-risk crop insurance program.
  • 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:
    • Rasaily, R. G.
    • He, J.
    • Li, H.
    • Zhang, X.
  • Source: International Agricultural Engineering Journal
  • Volume: 20
  • Issue: 2
  • Year: 2011
  • Summary: Due to the problem of residues blocking and seriously damaged bed shape during the planting of wheat in maize stubble coverage fields under the condition of permanent raised beds in irrigated agricultural region of Northwest China, the throwing stubble and renovating the bed type no-till planter for wheat was designed. This paper mainly analyzed the reshaping plough, moving cutter and throwing stubble device. Furthermore, the key parameters were analyzed and determined. The field experiment showed that through adopting the anti-blocking principle that combined moving cutter and throwing stubble device and residue-cutting by knife type opener, the machine could solve the residue and weed blocking problem effectively. It also has a good performance of passing and cutting stubble, and renovating the beds. The seeding and fertilizing depths acquired by the planter were 47.2 mm and 85.6 mm, respectively, which indicates the planter could meet the requirements of wheat no-tillage planting in permanent raised beds farming system in agricultural region of Northwest China.
  • 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.
  • Authors:
    • Radicetti, E.
    • Mancinelli, R.
    • Campiglia, E.
    • Marinari, S.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 89
  • Issue: 3
  • Year: 2011
  • Summary: There is not sufficient knowledge concerning the risks involved in NO 3-N leaching in relation to the use of cover crops and mulches. A 2 year field experiment was carried out in a pepper ( Capsicum annuum L.) crop transplanted into different soil management treatments which involved the addition of mulch of three different types of winter cover crops (CC) [hairy vetch ( Vicia villosa Roth.), subclover ( Trifolium subterraneum L.), and a mixture of hairy vetch/oat ( Avena sativa L.)], and an un-mulched plot. At the time of CC conversion into mulch, the hairy vetch/oat mixture accumulated the highest aboveground biomass (5.30 t ha -1 of DM), while hairy vetch in pure stand accumulated the highest quantity of N (177 kg ha -1) and showed the lowest C/N ratio (12). The marketable pepper yield was higher in mulched than in conventional (on average 33.5, 28.9, 27.7 and 22.2 t ha -1 of FM for hairy vetch, subclover, hairy vetch/oat mixture, and conventional, respectively). Generally, the NO 3-N content of the soil was minimum at CC sowing, slightly higher at pepper transplanting and maximum at pepper harvesting (on average 15.2, 16.8, and 23.3 mg NO 3-N kg -1 of dry soil, respectively). The cumulative leachate was higher during the CC period (from October to April) than the pepper crop period (from April to September), on average 102.1 vs 66.1 mm over the years, respectively. The cumulative NO 3-N leached greatly depended on the type of mulch and it was 102.3, 95.3, 94.7, and 48.2 kg ha -1 in hairy vetch, subclover, hairy vetch/oat mixture, and conventional, respectively. A positive linear correlation was found between the N accumulated in the CC aboveground biomass and the NO 3-N leached during pepper cultivation ( R2=0.87). This research shows that winter legume cover crops, especially hairy vetch in pure stand, converted into dead mulch in spring could be used successfully for adding N to the soil and increasing the yield of the following pepper crop although the risks of N losses via leaching could be increased compared to an un-mulched soil. Therefore when leguminous mulches are used in the cultivation of a summer crop, appropriate management practices of the system, such as a better control of the amount of irrigation water and the cultivation of a graminaceous or a cruciferous catch crop after the harvesting of the summer crop, should be adopted in order to avoid an increase in NO 3-N leaching.