• Authors:
    • Hoogmoed, W. B.
    • Cai, D.
    • Zhao, Q.
    • Wang, Y.
    • Zhang, X.
    • Zhang, D.
    • Dai, K.
    • Wang, X.
    • Oenema, O.
  • Source: Field Crops Research
  • Volume: 120
  • Issue: 1
  • Year: 2011
  • Summary: Rainfed crop production in northern China is constrained by low and variable rainfall. This study explored the effects of tillage/crop residue and nutrient management practices on maize ( Zea mays L.) yield, water use efficiency (WUE), and N agronomic use efficiency (NAE) at Shouyang Dryland Farming Experimental Station in northern China during 2003-2008. The experiment was set-up using a split-plot design with 3 tillage/crop residue methods as main treatments: conventional, reduced (till with crop residue incorporated in fall but no-till in spring), and no-till (with crop residue mulching in fall). Sub-treatments were 3 NP fertilizer rates: 105-46, 179-78 and 210-92 kg N and P ha -1. Maize grain yields were greatly influenced by the growing season rainfall and soil water contents at sowing. Mean grain yields over the 6-year period in response to tillage/crop residue treatments were 5604, 5347 and 5185 kg ha -1, under reduced, no-till and conventional tillage, respectively. Grain yields under no-till, were generally higher (+19%) in dry years but lower (-7%) in wet years. Mean WUE was 13.7, 13.6 and 12.6 kg ha -1 mm -1 under reduced, no-till, and conventional tillage, respectively. The no-till treatment had 8-12% more water in the soil profiles than the conventional and reduced tillage treatments at sowing and harvest time. Grain yields, WUE and NAE were highest with the lowest NP fertilizer application rates (at 105 kg N and 46 kg P ha -1) under reduced tillage, while yields and WUE tended to be higher with additional NP fertilizer rates under conventional tillage, however, there was no significant yield increase above the optimum fertilizer rate. In conclusion, maize grain yields, WUE and NAE were highest under reduced tillage at modest NP fertilizer application rates of 105 kg N and 46 kg P ha -1. No-till increased soil water storage by 8-12% and improved WUE compared to conventional tillage, thus showing potentials for drought mitigation and economic use of fertilizers in drought-prone rainfed conditions in northern China.
  • Authors:
    • Wu, Z. J.
    • Zhu, A. N.
    • Chen, L. J.
    • Chen, Z. H.
    • Wang, J. B.
  • Source: Plant, Soil and Environment
  • Volume: 57
  • Issue: 6
  • Year: 2011
  • Summary: The effects of tillage and residue input amounts on soil phosphatase (alkaline phosphomonoesterase ALP, acid phosphomonoesterase ACP, phosphodiesterase PD, and inorganic pyrophosphatase IPP) activities and soil phosphorus (P) forms (total P, organic P, and available P) were evaluated using soils collected from a three-year experiment. The results showed that no-till increased soil total and organic P, but not available P as compared to conventional tillage treatments. Total P was increased as inputs of crop residue increased for no-till treatment. There were higher ALP and IPP activities in no-till treatments, while higher PD activity was found in tillage treatments and tillage had no significant effect on ACP activity. Overall phosphatase activities increased with an increase of crop residue amounts. Soil total P was correlated negatively with PD activity and positively with other phosphatase activities. Organic P had a positive correlation with ACP activity, but a negative correlation with PD activity. Available P had no significant correlation with phosphatase activities. Our data suggests that no-till and residue input could increase soil P contents and enhance the activities of phosphatase.
  • Authors:
    • Torbert, H. A.
    • Watts, D. B.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 5
  • Year: 2011
  • Summary: Reduced tillage, poultry litter applications, crop rotations, and winter cover cropping are management practices that could be used with conservation tillage systems to increase yields compared to conventional monoculture systems. This study evaluated cropping sequences of corn ( Zea mays L.), soybean [ Glycine max (L.) Merr.], and corn-soybean rotations with wheat ( Triticum aestivum L.) covers in conventional, strip, and no-tillage (no-till) systems, following poultry litter additions to wheat cover. The study was conducted from 1991 to 2001 on a Hartsells fine sandy loam (fine-loamy, siliceous, subactive, thermic Typic Hapludults). Poultry litter (112 kg N ha -1) was applied to wheat each year in fall. Wheat not receiving poultry litter received equivalent inorganic N. Corn was fertilized with inorganic fertilizer in spring with 56 kg N ha -1 at planting followed by 168 kg N ha -1 3 wk after emergence; soybean received no fertilizer. Corn yields were influenced by tillage in 1991, 1992, 1993, 1994, 1996, 1997, 1998, and 2001 with conventional tillage producing greater yields, except in 1993 (strip tillage) and 2001 (no-till). Poultry litter increased corn yield in 1991, 1997, and 1998. Crop rotations increased corn yield for all years, except 2001. Soybean yields were not impacted by differences in tillage. Crop rotations significantly impacted soybean yield in 1992, 1995, and 1998, with higher yields observed in 1992, and 1995, and lower yields in 1998. Poultry litter significantly increased soybean yield 8 of the 9 yr evaluated. This study suggests that poultry litter use for these crop rotations in conservation tillage systems could increase sustainable yield production.
  • Authors:
    • White, C. M.
    • Weil, R. R.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 1
  • Year: 2011
  • Summary: Cover crops can influence nutrient cycling in the agroecosystem. Forage radish (FR) (Raphanus sativus L. var. longipinnatus) is unique in terms of P cycling because of its high tissue P concentration, rapid growth in the fall, and rapid decomposition in winter and spring. In addition, FR produces a taproot that decays during the winter and leaves distinct holes in the surface soil. This study measured P uptake by FR and cereal rye (CR) (Secale cereale L.) cover crops; the Mehlich 3 P concentration (M3P) in bulk soil following FR, CR, and no cover crop (NC); and M3P in soil within 3 cm of FR taproot holes. Cover crop treatments of FR, CR, and NC were established at two sites each fall for three subsequent years in a cover crop-corn (Zea mays L.) silage rotation. Cover crop shoot P uptake ranged from 5.9 to 25 kg P ha(-1) for FR measured in the fall and from 3.0 to 26 kg P ha(-1) for CR measured in the spring. The greatest cover crop effect on bulk soil M3P was observed at the 0- to 2.5-cm depth aft er 3 yr of cover crops, with M3P values of 101, 82, and 79 mg P kg(-1) aft er FR, CR, and NC, respectively. Soil within 3 cm of FR taproot holes had greater M3P than FR and NC bulk soil. Further studies should be conducted to determine if FR could increase P removal rates in excessively high P soils or increase P availability in low P soils.
  • Authors:
    • Chen, G. H.
    • Khalilian, A.
    • Wiatrak, P.
  • Source: American Journal of Agricultural and Biological Sciences
  • Volume: 6
  • Issue: 1
  • Year: 2011
  • Summary: Problem statement: Insufficient rainfall under low yield environment may affect nitrogen management, plant growth indices and grain yields of corn ( Zea mays L.). Approach: The objective of this study was to determine the effects of two N application timings (all at planting and as split application with N applied at planting and V6 stage) and five N fertilizer rates (0, 45, 90, 135 and 180 kg N ha -1) on strip-tilled, dryland corn growth and yields under low-yield environmental conditions near Blackville SC, from 2007-2009. Plant growth measurements included plant height, ear height, relative chlorophyll content (SPAD), Leaf Area Index (LAI) and normalized difference vegetation index (NDVI). Results: Plant LAI at V8, NDVI at V8 and R1, SPAD at R1, plant height at V8 and grain yield generally increased with increasing N application rates. Due to most likely insufficient precipitation, the N application timing did not affect corn growth or yield. Despite relatively low grain yields, corn yield was increased by 1.6 Mg ha -1 with increasing N application rate of 100 kg ha -1. Grain yield was positively correlated with plant leaf area index (LAI) at R1 (r=0.27, p≤0.05) and Normalized Difference Vegetation Index (NDVI) at V8 and R1 (r=0.33 and 0.29, p≤0.01, respectively) and plant height at V8 stage (r=0.42, p≤0.001). With N applied at planting, there was a 0.55 and 0.49 Mg ha -1 yield increase with 0.1 increases in plant NDVI at V8 and R1, respectively. Conclusion: Under strip tillage and low yield environment conditions, plant growth and yields may not be affected by timing of N application mainly due to insufficient rainfall. Plant NDVI (for treatments with all N applied at planting) at V8 and R1 can help to estimate potential of corn grain yield, which may be reduced due to low nitrogen use efficiency.
  • Authors:
    • Holmes, P.
    • Wiggs, G.
  • Source: Earth Surface Processes and Landforms
  • Volume: 36
  • Issue: 6
  • Year: 2011
  • Summary: The west-central part of South Africa's Free State Province falls within the transition zone between South Africa's sub-humid, temperate grasslands to the east, and the semi-arid Karoo and arid Kalahari to the south and west, respectively. The area is characterized by low rainfall (typically 500 mm or less) with high variability, but environmental conditions allow widespread dryland commercial agriculture (maize, sunflowers and stock farming). However, human activity promotes wind erosion and the area is susceptible to dust emissions. This study is the first to quantify the degree of wind erosion on the agricultural soils in the region under prevailing winter to spring climatic conditions and land management practices. Using arrays of cup anemometers, dust deposition traps and saltation impact sensors (Safires), measurements were made of the key erosivity and erodibility drivers that control the degree of wind erosion. Results demonstrate that significant quantities of dust are mobilized, particularly during the months of September and October. Thresholds of wind erosion are shown to respond particularly closely to changes in surface and aerodynamic roughness ( z0) with the amount of collected dust correlating well with measures of wind erosivity that weight the impact of higher wind speeds. Given the importance of surface roughness in controlling erosion thresholds, results show that the opportunity exists for well designed farming practices to control wind erosion. However, it is likely that climatically driven environmental change will impact on some of the identified controls on erosion (wind power, moisture availability) with the result that the wind erosion hazard is likely to increase within this marginal environment.
  • Authors:
    • Yang, Z.
    • Guan, C.
    • Zhou, H.
    • Fan, G.
    • Xie, W.
  • Source: Nongye Jixie Xuebao = Transactions of the Chinese Society for Agricultural Machinery
  • Volume: 42
  • Issue: 11
  • Year: 2011
  • Summary: Based on the results from 18-year long-term location experiment in dryland experimental area of northern China, the effects of various kinds of straw return to field such as no straw returning (CK), straw mulching (SM), straw crushing (SC), cattle manure (CM) and different fertilization time i. e. spring and autumn on corn yield and water use efficiency were studied. The results showed that the experiment of combining autumn fertilizing with returning stalks to field could increase the yield and water use efficiency of spring maize significantly compared to the spring fertilizing, meanwhile, it decreased the accumulated water consumption and increased the soil water storage amount. The results showed that autumn fertilizing increased 9.71-15.58 t/hm 2 in yield, compared with spring fertilizing. The range of increased in yield was 8.33%-16.19%. The total corn yield and water use efficiency in the past 18-year decreased in the following order: CM > SM > SC > CK. In different rainfall years, the corn yield and water use efficiency were very different. In normal years, the corn yield was highest. In dry years, the water use efficiency of spring maize was highest and yield increasing effect from straw mulching combining with autumn fertilizing was striking.
  • 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:
    • 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.