• Authors:
    • Erenstein, O.
  • Source: Agricultural Water Management
  • Volume: 96
  • Issue: 12
  • Year: 2009
  • Summary: The intensive irrigated rice-wheat systems in the northwest Indo-Gangetic Plains of South Asia are built on a long tradition of canal irrigation and the more recent advent of tubewells. Findings from farm surveys are used to examine water management and water productivity in the rice-wheat belt of India's Haryana State and Pakistan's Punjab province. Attributes of the irrigation sources help explain the widespread interest in groundwater use and the relative demise of canal water use. In each area groundwater now is the main irrigation source, used either solely or in conjunction with surface water. The ownership of tubewells is near universal among the surveyed farms, whereas conjunctive water use is more widespread during the monsoon season, among better endowed farmers and in the Pakistan Punjab. In Pakistan Punjab farmers primarily rely on diesel powered tubewells whereas Haryana farmers mainly use relatively cheaper electric power. Water productivity indicators for rice are markedly lower than those for wheat - largely reflecting significantly higher water inputs in paddy cultivation - but also vary between the study areas and by the prevailing water use, reflecting the limited incentives for farmers to use water wisely. A combination of technological, land use and market based approaches is likely to be most effective in achieving sustainable water management in these intensive cereal systems.
  • Authors:
    • Eckard, R.
    • Henry, B.
  • Source: Tropical Grasslands
  • Volume: 43
  • Year: 2009
  • Summary: Agriculture is responsible for a significant proportion of total anthropogenic greenhouse gas emissions (perhaps 18% globally), and therefore has the potential to contribute to efforts to reduce emissions as a means of minimising the risk of dangerous climate change. The largest contributions to emissions are attributed to ruminant methane production and nitrous oxide from animal waste and fertilised soils. Further, livestock, including ruminants, are an important component of global and Australian food production and there is a growing demand for animal protein sources. At the same time as governments and the community strengthen objectives to reduce greenhouse gas emissions, there are growing concerns about global food security. This paper provides an overview of a number of options for reducing methane and nitrous oxide emissions from ruminant production systems in Australia, while maintaining productivity to contribute to both objectives. Options include strategies for feed modification, animal breeding and herd management, rumen manipulation and animal waste and fertiliser management. Using currently available strategies, some reductions in emissions can be achieved, but practical commercially available techniques for significant reductions in methane emissions, particularly from extensive livestock production systems, will require greater time and resource investment. Decreases in the levels of emissions from these ruminant systems (i.e., the amount of emissions per unit of product such as meat) have already been achieved. However, the technology has not yet been developed for eliminating production of methane from the rumen of cattle and sheep digesting the cellulose and lignin-rich grasses that make up a large part of the diet of animals grazing natural pastures, particularly in arid and semi-arid grazing lands. Nevertheless, the abatement that can be achieved will contribute significantly towards reaching greenhouse gas emissions reduction targets
  • Authors:
    • Blignaut, J.
    • Ueckermann, L.
    • Aronson, J.
  • Source: South African Journal of Science
  • Volume: 105
  • Issue: 1/2
  • Year: 2009
  • Summary: South Africa in general has been approximately 2% hotter and at least 6% drier over the ten years between 1997 and 2006 compared to the 1970s. The use of water has also increased greatly over this same period. By 2000, 98.6% of that year's surface water yield and 41% of the annual utilisable potential of groundwater was allocated to use. Irrigation agriculture, comprising 60% of total consumption, is by far the largest single consumer of water. Given these climatic and water use changes as a backdrop, we employed a panel data econometric model to estimate how sensitive the nation's agriculture may be to changes in rainfall. Net agricultural income in the provinces, contributing 10% or more to total production of both field crops and horticulture, is likely to be negatively affected by a decline in rainfall, especially rain-fed agriculture. For the country as a whole, each 1% decline in rainfall is likely to lead to a 1.1% decline in the production of maize (a summer grain) and a 0.5% decline in winter wheat. These results are discussed with respect to both established and emerging farmers, and the type of agriculture that should be favoured or phased out in different parts of the country, in view of current and projected trends in climate, increasing water use, and declining water availability.
  • Authors:
    • Hunt, J. R.
    • Dalgliesh, N. P.
    • McCown, R. L.
    • Whish, J. P. M.
    • Robertson, M. J.
    • Foale, M. A.
    • Poulton, P. L.
    • Rees, H. van
    • Carberry, P. S.
    • Hochman, Z.
  • Source: Crop & Pasture Science
  • Volume: 60
  • Issue: 11
  • Year: 2009
  • Summary: Crop simulation models relevant to real-world agriculture have been a rationale for model development over many years. However, as crop models are generally developed and tested against experimental data and with large systematic gaps often reported between experimental and farmer yields, the relevance of simulated yields to the commercial yields of field crops may be questioned. This is the third paper in a series which describes a substantial effort to deliver model-based decision support to Australian farmers. First, the performance of the cropping systems simulator, APSIM, in simulating commercial crop yields is reported across a range of field crops and agricultural regions. Second, how APSIM is used in gaining farmer credibility for their planning and decision making is described using actual case studies. Information was collated on APSIM performance in simulating the yields of over 700 commercial crops of barley, canola, chickpea, cotton, maize, mungbean, sorghum, sugarcane, and wheat monitored over the period 1992 to 2007 in all cropping regions of Australia. This evidence indicated that APSIM can predict the performance of commercial crops at a level close to that reported for its performance against experimental yields. Importantly, an essential requirement for simulating commercial yields across the Australian dryland cropping regions is to accurately describe the resources available to the crop being simulated, particularly soil water and nitrogen. Five case studies of using APSIM with farmers are described in order to demonstrate how model credibility was gained in the context of each circumstance. The proposed process for creating mutual understanding and credibility involved dealing with immediate questions of the involved farmers, contextualising the simulations to the specific situation in question, providing simulation outputs in an iterative process, and together reviewing the ensuing seasonal results against provided simulations. This paper is distinct from many other reports testing the performance and utility of cropping systems models. Here, the measured yields are from commercial crops not experimental plots and the described applications were from real-life situations identified by farmers. A key conclusion, from 17 years of effort, is the proven ability of APSIM to simulate yields from commercial crops provided soil properties are well characterised. Thus, the ambition of models being relevant to real-world agriculture is indeed attainable, at least in situations where biotic stresses are manageable.
  • Authors:
    • Lal,R.
    • Dubey,A.
  • Source: Journal of Crop Improvement
  • Volume: 23
  • Issue: 4
  • Year: 2009
  • Summary: Sustainability of agricultural systems depends on their carbon (C) footprint, and the C output:C input ratio. Thus, this study was conducted with the objectives to: (i) assess the agricultural C emissions in relation to predominant farming systems in Punjab, India, and Ohio, USA; (ii) evaluate C-use efficiency of production systems; and (iii) determine the relative sustainability of agronomic production systems as determined by their C footprints. The data collated on C-based input into the soil for predominant crops for both regions included the amounts of fertilizers (N, P, K), herbicides and pesticides used for each crop annually, tillage methods, cropland area, total production of each crop, area under different farming systems, water-management practices (e.g., tubewell irrigation), and total number of livestock. These data were used to compute C equivalent (CE) per hectare of input and output, and the relative sustainability indices as a measure of the C-production efficiency. There existed a linear relationship observed between C input and C output for Punjab, indicating that an increase of 1 Tg/yr (1 Tg=teragram=10 12 g=million ton) of C input resulted in the corresponding C output of ~12 Tg/yr. A similar linear relationship between input and net C output between the 1930s and 1980s was observed for Ohio, and the ratio reached a plateau during 1990s. The average C-sustainability index (increase in C output as % of C-based input) value for Ohio from 1990 to 2005 was 35-43, almost 2.5 times that of Punjab. Since 1989, there has been a major shift in Ohio from conventional tillage to reduced and conservation tillage along with a decline in fertilizer use. No-till farming is practiced on about 35% of the cultivated area, which involves elimination of plowing, retention of crop residue mulch, and judicious use of chemicals. In Punjab, crop residues are removed, resulting in loss of C from the soil organic carbon pool. Hence, the C-based sustainability index is much higher in Ohio than in Punjab. C-efficient systems are more sustainable than inefficient farming systems, and residue removal reduces agricultural sustainability by depleting the soil C pool.
  • Authors:
    • Six, J.
    • Howitt, R. E.
    • Catalá-Luque, R.
    • Albarracin, M. V.
    • De Gryze, S.
  • Source: California Agriculture
  • Volume: 63
  • Issue: 2
  • Year: 2009
  • Summary: Agricultural management has a significant impact on the amount of greenhouse gases emitted by cropped fields. Alternative practices such as winter cover cropping and avoiding overfertilization can decrease the total amount of greenhouse gases that are produced. Policymakers are considering a structure in which parties (such as factories) who exceed their greenhouse-gas emissions cap can pay incentives to encourage farmers to adopt practices that curb greenhouse gases. Based on data from field studies and an ecosystem computer model, we assessed impacts on yields and the total potential for reducing greenhouse-gas emissions of certain alternative practices in California.
  • Authors:
    • Wong, C. P.
    • Neely, C. L.
    • Schohr, T.
    • Oldfield, J. T.
    • Laca, E. A.
    • Kustin, C.
    • George, M. R.
    • Brown, J. R.
    • Alvarez, P.
    • Fynn, A. J.
  • Year: 2009
  • Authors:
    • Torabi, M.
    • Hosni, M.
    • Vaezi, B.
    • Khanzadeh, H.
    • Khalilzadeh, G.
    • Hosseinpour, T.
    • Nourinia, A.
    • Roustaei, M.
    • Mohammadi, M.
    • Patpour, M.
    • Dehghan, M.
  • Source: Seed and Plant Improvement Journal
  • Volume: 25-1
  • Issue: 3
  • Year: 2009
  • Summary: Some parts of semitropical regions in Khouzestan, Fars, Kohgiloyieh-va-Boyrahmad, Lorestan, Golestan, Ardabil, Kermanshah and Boushehr provinces specified to spring barley cultivation which local or a few improved cultivars are grown there. Barley breeding activities in Dryland Agricultural Research Institute(DARI) are continuously undertaken in Gachsaran, Kouhdasht, Gonbad and Moghan to introduce new cultivars for these regions. Obtained results during 11 years (1993-2003) showed that genotype Wi2291/Wi2269//Er/Apm originated from ICARDA, had good adaptation, yield stability and good agronomic traits in dryland areas with semitropical climate. The average yield of this genotype in all locations was 3.556 tha -1 which was 12 percent more than the yield of Izeh as improved check. Higher thousand kernel weight (more than 10 gram in some locations) is a remarkable trait of this genotype. The new genotype is a spring type barley with an average plant height of 72 cm and resistant to lodging. This genotype was introduced through Agricultural Extension, Education and Research Organization under the name of Mahoor in 2008.
  • Authors:
    • Kushwaha, S. S.
    • Gajja, B. L.
  • Source: Current Agriculture
  • Volume: 33
  • Issue: 1/2
  • Year: 2009
  • Summary: An attempt has been made to document the change in the cropping pattern in Rajasthan, India. The study was based on the secondary data from 1980-81 to 2006-07. There was no major change in the cropping pattern, but in some crops such as rape, mustard and soyabean a shift was recorded. The increase in irrigation facilities in the state had observed increase in irrigated crops such as cotton, groundnut in some parts, wheat, soyabean, rape and mustard while some crops had witnessed the reduction in area. This indicated some minor change in the cropping pattern. However, the cropping pattern was mainly influenced by physical, economic, technological and institutional factors such as capital and market location and price of the crop at harvest time had definite temporal changes. The crop diversification had been witnessed in favour of oilseed crops.
  • Authors:
    • Ghanbari, A.
    • Daneshiyan, J.
    • Galavi, M.
    • Mousavi, S. M. P.
    • Basirani, N.
    • Jonoobi, P.
  • Source: Iranian Journal of Field Crop Science
  • Volume: 40
  • Issue: 1
  • Year: 2009
  • Summary: In order to investigate the effect of animal manure application, in drought stress conditions, on soybean (Glycine max L.) quantitative and qualitative characters, an experiment in the form of split plot and based on randomized complete block design of four replications was conducted at Seed and Plant Improvement Institute, in 2004. Irrigation treatments as the main factor were in three levels of 50 (control), 100 (medium stress) and 150 mm (severe stress) water evaporation from Class A Pan, and manure application as sub plot at four levels of 0, 15, 30 and 45 t/ha. Plants were irrigated at 50 mm evaporation from pan of class A, from V3 germinative stage (trifoliate exposed). Drought stress decreased plant height, number of nodes, internode length, number of branches, number of pods and seed weight per m 2 as well as 1000 seed weight. Animal manure application reduced drought stress effects. The yield decreased with when drought stress intensity increasing. Increase in animal manure application increased seed yield. The highest yield was obtained in control with 2511 kg/h. Water stress reduced grain yield in medium and severe stress treatments by 22% and 39%, respectively. Application of 45t/h of animal manure produced the highest yield of 2244 kg/h. Increase in animal manure application increase caused in number of pods per m 2 and in 1000 seed weight. Seed oil content decreased while protein content increasing, when drought stress intensity increased. Animal manure exerted a significant effect on seed protein content, the lowest seed protein content being obtained at 45 t/ha of manure application.