• Authors:
    • Tahir, M. A.
    • Quddus, M. A.
    • Muhammad, A.
    • Muhammad, A.
    • Nighat, F.
  • Source: Pakistani Journal of Agricultural Science
  • Volume: 48
  • Issue: 1
  • Year: 2011
  • Summary: The paper examined the resource use efficiency of small Bt cotton farmers of Punjab province of Pakistan using the production function approach. Data for the study were obtained from 150 randomly selected Bt cotton farmers from Punjab province using a multistage sampling procedure and then categorized into small, medium and large farmers. Average farm size of small farmer was found to be 5 acres. Regression results indicated that Fertilizer, Spray Number, Irrigation acre inch and labour cost were significantly affecting Bt cotton production while farm size was found non significant. The resource use efficiency analysis showed that efficiency ratios i.e. MVP/MFC for inputs fertilizer (Kg), spray number, irrigation (acre inch) and labour cost (Rs) were found to be 1.5, 3.94, 3.01 and 1.27, respectively. All the efficiency ratios, more than unity indicated the under utilization of all the production inputs under consideration in case of small Bt cotton farmers. Bt cotton production for small Bt farmers had an increasing return to scale with elasticity of production 1.27. Opportunities still exists to increase Bt cotton output in the study area by increasing the level of above mentioned productive resources.
  • Authors:
    • Murari, L.
  • Source: Regional Environmental Change
  • Volume: 11
  • Issue: Supplement 1
  • Year: 2011
  • Summary: One of the targets of the United Nations 'Millennium Development Goals' adopted in 2000 is to cut in half the number of people who are suffering from hunger between 1990 and 2015. However, crop yield growth has slowed down in much of the world because of declining investments in agricultural research, irrigation, and rural infrastructure and increasing water scarcity. New challenges to food security are posed by accelerated climatic change. Considerable uncertainties remain as to when, where and how climate change will affect agricultural production. Even less is known about how climate change might influence other aspects that determine food security, such as accessibility of food for various societal groups and the stability of food supply. This paper presents the likely impacts of thermal and hydrological stresses as a consequence of projected climate change in the future potential agriculture productivity in South Asia based on the crop simulation studies with a view to identify critical climate thresholds for sustained food productivity in the region. The study suggests that, on an aggregate level, there might not be a significant impact of global warming on food production of South Asia in the short term (
  • Authors:
    • Sheffield, K. J.
    • Abuzar, M.
    • Whitfield, D. M.
    • O'Connell, M. G.
    • McClymont, L.
    • McAllister, A. T.
  • Source: Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: SEBAL-METRIC estimates of evapotranspiration (ET) were derived from Landsat-5 imagery of Sunraysia Irrigation Region of Victoria, Australia. Paired estimates of ET and vegetation cover, NDVI, were derived from an image taken mid-season on 5 January 2009. NDVI and ET were attributed to land use based on data provided by SunRISE21 Inc. Relationships between ET, scaled by field measured reference tall crop evapotranspiration, ET r, and NDVI for the dominant almond, citrus and grape crops showed that the evaporation ratio (ET/ET r) was strongly related to NDVI. These findings suggest that SEBAL-METRIC satellite remote sensing approaches offer an affordable and robust method for the deviation of NDVI-based block-customised estimates of crop coefficient (K c) for almond, citrus and grape crops.
  • Authors:
    • Grace, P.
    • Barton, L.
    • Chen, D.
    • Eckard, R.
    • Kelly, K.
    • Officer, S.
    • Scheer, C.
    • Schwenke, G.
    • Wang, W.
  • Source: Soil Solutions for a Changing World
  • Year: 2011
  • Authors:
    • Van Zwieten, L.
    • Kimber, S.
    • Rowlings, D. W.
    • Grace, P. R.
    • Scheer, C.
  • Source: Plant and Soil
  • Volume: 345
  • Issue: 1-2
  • Year: 2011
  • Summary: We assessed the effect of biochar incorporation into the soil on the soil-atmosphere exchange of the greenhouse gases (GHG) from an intensive subtropical pasture. For this, we measured N2O, CH4 and CO2 emissions with high temporal resolution from April to June 2009 in an existing factorial experiment where cattle feedlot biochar had been applied at 10 t ha−1 in November 2006. Over the whole measurement period, significant emissions of N2O and CO2 were observed, whereas a net uptake of CH4 was measured. N2O emissions were found to be highly episodic with one major emission pulse (up to 502 μg N2O-N m−2 h−1) following heavy rainfall. There was no significant difference in the net flux of GHGs from the biochar amended vs. the control plots. Our results demonstrate that intensively managed subtropical pastures on ferrosols in northern New South Wales of Australia can be a significant source of GHG. Our hypothesis that the application of biochar would lead to a reduction in emissions of GHG from soils was not supported in this field assessment. Additional studies with longer observation periods are needed to clarify the long term effect of biochar amendment on soil microbial processes and the emission of GHGs under field conditions.
  • Authors:
    • Herr, A.
    • Dunlop, M.
  • Source: Biomass and Bioenergy
  • Volume: 35
  • Issue: 5
  • Year: 2011
  • 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:
    • Flower, K. C.
    • Crabtree, W. L.
  • Source: Field Crops Research
  • Volume: 121
  • Issue: 1
  • Year: 2011
  • Summary: On acid soils, no-tillage farmers are often advised to apply lime to the soil surface without incorporation by tillage. As such, it can take a number of years before the subsoil acidity is decreased. However, no-tillage seeders vary in the level of soil disturbance caused during seed placement. The consequence of such variations in soil disturbance for the effectiveness of lime in no-tillage cropping has not been explored. Our objectives were (i) to determine if the liming effect could be accelerated by increasing the rate of lime and level of soil disturbance during no-tillage seeding, and (ii) evaluate the effect of no-tillage seeding method, rate of lime and soil pH on yield of wheat, barley, canola and lupins. Three trials, each with a factorial design consisting of four seeding methods and four lime rates, were established in 1999 and continued until 2005. The soil had a texture contrast with about 15-20 cm of sand over yellow sandy clay loam and the initial pH (CaCl 2) at both 0-10 and 10-20 cm was between 4.5 and 4.7. The four seeding treatments were: low disturbance zero-till disc openers (ZT), higher disturbance no-tillage tines with narrow knife-points (NT), higher disturbance full cut seeding with sweeps (FC) for the first three years followed by ZT from then on, and FC for the first year followed by NT thereafter. The four lime rates were 0, 1, 2 and 4 t ha -1. The liming effect was more rapid with the higher disturbance seeding of NT, FCZT and FCNT, compared with ZT; the seeding effect on soil pH diminished with time and was not detected in the subsoil after four years. Higher rates of lime increased this effect and there was no interaction between seeding method and lime rate. This indicated that soil pH under the different seeding methods responded in a similar manner to increased lime. Nonetheless, significant positive linear regressions were found between yield and soil pH for wheat and barley and a negative relationship for lupins. Canola showed no response to soil pH, possibly because establishment was affected by seeding method, and soil pH was not low enough to elicit a response. The ZT seeding method gave lower yields than the other methods for canola and lupins in some years, but had no effect on wheat and barley yields. Higher disturbance at the time of no-till seeding can, therefore, accelerate the liming effect, making earlier economic gains possible.
  • Authors:
    • Gregoret, M. C.
    • Diaz Zorita, M.
    • Dardanelli, J.
    • Bongiovanni, R. G.
  • Source: Precision Agriculture
  • Volume: 12
  • Issue: 6
  • Year: 2011
  • Summary: In semi-arid regions, soil water and nitrogen (N) are generally limiting factors for corn ( Zea mays L.) production; hence, implementation of appropriate N fertilization strategies is needed. The use of precision agriculture practices based on specific site and crop properties may contribute to a better allocation of fertilizer among management zones (MZ). The aim of this study was to develop a model for diagnosis of N availability and recommendation of N fertilizer rates adjusted to MZ for dryland corn crops growing in Haplustolls. The model considered variability between MZ by including site-specific variables [soil available water content at sowing (SAW) and Available Nitrogen (soil available N-NO 3 at planting+applied N, Nd)] using spatial statistical analysis. The study was conducted in Cordoba, Argentina in Haplustolls and consisted in four field trials of N fertilizer (range 0-161 kg N ha -1) in each MZ. The MZ were selected based on elevation maps analysis. Grain yields varied between MZ and increased with larger SAW and Nd at sowing. Grain responses to Nd and SAW in any MZ were not different between sites, allowing to fit a regional model whose parameters (Nd, Nd 2, SAW, SAW 2) contributed significantly ( p<0.001) to yield prediction. Agronomical and economically optimum N rates varied among MZs. However, the spatial variability of optimum N rates among MZs within sites was not enough to recommend variable N fertilizer rates instead of a uniform rate. Variable N fertilizer rates should be recommended only if variability in SAW and soil N among MZ is greater than that found in this work.
  • Authors:
    • He, Jin
    • Li, HongWen
    • Wang, QingJie
    • Zhang, XiRui
    • Li, Hui
    • Zhang, DongYuan
  • Source: Nongye Jixie Xuebao (Transactions of the Chinese Society of Agricultural Machinery)
  • Volume: 42
  • Issue: 10
  • Year: 2011
  • Summary: According to the problems of few available no-till seeders and residues-blocking and bed-damaging during the seeding of wheat in maize residues cover fields in permanent raised beds (PRB) in northwest oasis farming areas, the new anti-blocking (residue-chopping and throwing by powered L-type hammering blade and residue-cutting by knife type opener) and bed renovation (bed-reshaping by double-wing plough) ideas were put forward. The powered hammering blade no-till wheat seeder for PRB was designed. The key parameters for L-type hammering blade, opener and double-wing plough were determined. The experiment in maize residue cover fields showed that the seeder was effective in solving residues blocking. Compared with 2BMF-5 no-till wheat seeder, the spring wheat yield was similar and bed renovation effect was better with the decreased soil disturbance.