• Authors:
    • Changade, N. M.
    • Khodke, U. M.
    • Chavan, M. L.
  • Source: International Journal of Agricultural Engineering
  • Volume: 2
  • Issue: 2
  • Year: 2009
  • Summary: Historical weather data can be used to develop and modify the management practices to increase the production with the conjunctive use of rain and irrigation water as per the water needs of the crop. Regional scale crop and water resource planning needs determination of reference crop evapotranspiration (eto), probability distribution of rainfall and ETo, and estimates of magnitude and duration of water deficit and surplus which can promote crop production in both irrigated and dryland areas. Daily weather data of 16 years (from 1984 to 2001) for five locations i.e., Aurangabad, Beed, Nanded, Parbhani and Osmanabad of Marathwada region was used to determine reference crop evapotranspiration (ETo). The rainfall and ETo data were analysed to ascertain their fit to various probability distributions. The goodness of fit was determined by chi 2 tests. The developed crop coefficients were used to estimate crop water requirements of 8 major crops of the region. Effective rainfall was used to determine the weeks at which the rainfall exceed or fall deficit of crop water requirement. The study indicated that normal distribution gave the closest fit to the weekly rainfall and ETo data. The seasonal water requirement of cotton, groundnut, sugarcane and banana is higher at Parbhani whereas that of kharif sorghum, rabi sorghum, wheat and soybean is higher at Osmanabad than other places in the region, the effective rainfall meets the water need of kharif sorghum and soybean. The rainfall values during the critical growth stages of rabi (sorghum and wheat) and summer crops (groundnut, banana and sugarcane) are deficit than their water requirement in the respective weeks and hence require irrigation during those periods. Among the row crops, wheat and groundnut can only be grown under irrigation. Annual excess rainfall for various crops ranges between 561-749 mm for kharif sorghum, 124-195 mm for rabi sorghum, 0-15 mm for wheat, 624-808 mm for soybean, 633-786 mm for cotton, 453-609 mm for sugarcane and 526-703 mm for banana. If the excess rains are effectively harvested, the irrigation potential could be raised in the region.
  • Authors:
    • de Alba, S.
    • Benito, G.
    • Lacasta, C.
    • Alcázar, M.
    • Alba, S. de
  • Source: Advances in Geoecology or Land degradation and rehabilitation: dryland ecosystems. Papers presented at the Fourth International Conference on Land Degradation, Cartagena, Murcia, Spain, 12-17 September 2004.
  • Volume: 40
  • Year: 2009
  • Summary: In Europe, especially in the Mediterranean area, water erosion seriously affects 50% to 70% of agricultural land. However, there is a lack of field-data on water erosion rates for agricultural areas in semiarid Mediterranean climates. This paper describes an experimental field station (La Higueruela Station) for the continuous monitoring of water erosion that was set up in 1992 in central Spain (Toledo, Castilla-La Mancha). In the study area, the annual precipitation is around 450 mm with a very irregular inter-annual and seasonal distribution, which includes a strong drought in summer. The geology is characterized by non-consolidated Miocene materials, mostly arcosics. The area presents a low relief and gentle slopes, generally
  • Authors:
    • Wasaya, A.
    • Asif, M.
    • Tanveer, A.
    • Nadeem, M. A.
    • Tahir, M.
    • Ali, A.
    • Jamil-ur-Rehman
  • Source: Pakistan Journal Of Life and Social Science
  • Volume: 7
  • Issue: 2
  • Year: 2009
  • Summary: In field experiment at Faisalabad, Pakistan conducted during August, 2005, the effect of different irrigation management strategies on growth and yield of soybean was investigated. The experiment comprised of eight irrigation practices of viz; rainfed, one irrigation at vegetative growth stage, one irrigation at flowering, one irrigation at pod formation, two irrigations at vegetative growth stage and at flowering, two irrigations at vegetative growth stage and at pod formation, two irrigations at flowering and at pod formation and three irrigations at vegetative growth stage, at flowering and at pod formation. Number of plants m -2, number of pods per plant, number of seeds per pod and seed yield was significantly higher when crop was irrigated with three irrigations at vegetative growth stage, at flowering and at pod formation.
  • Authors:
    • Janzen, H. H.
    • Ellert, B. H.
  • Source: Canadian Journal of Soil Science
  • Volume: 88
  • Issue: 2
  • Year: 2008
  • Summary: Irrigated land in southern Alberta is intensively managed, producing high yields but also requiring higher inputs, notably of nitrogen (N), than adjacent rainfed lands. The higher N inputs, combined with enhanced soil moisture, might stimulate nitrous oxide (N2O) emissions, but the influence of management on these emissions has not been widely studied. Our objective was to assess soil N2O emissions, along with those of carbon dioxide (CO2) and of methane (CH4), from irrigated cropping systems as influenced by source of N. We used a chamber technique to measure year-round emissions for 3 yr in long-term irrigated crop rotations receiving N as legume crop residues, non-legume crop residues, livestock manure or ammonium nitrate fertilizer. Unlike CO2 fluxes, which peaked during the growing season, those of N2O showed no consistent seasonal trends; emissions occurred sporadically in bursts throughout the year. Depending on management practices, 0.4 to 4.0 kg N2O-N ha(-1) yr(-1) was emitted to the atmosphere. The amount of N2O emitted from the alfalfa system, averaged over all manure and fertilizer N amendments, was more than twofold that emitted from the corn system. The proportions of fertilizer-N released as N2O were 0.95% for the alfalfa system and 1.30% for the corn system. After livestock manure or legume residues were incorporated, soil CO2 and N2O emissions appeared to be intertwined, but during the early spring N2O emissions were decoupled from CO2. Furthermore, N2O emissions were highly variable in space; at three of 54 chambers, N2O fluxes were consistently 12 to 55 times greater than those for other chambers in the same treatment. Such complexity conceals the underlying processes of net N2O production and transport to the soil surface.
  • Authors:
    • De Moura, R. L.
    • Klonsky, K. M.
    • Marsh, B. H.
    • Frate, C. A.
  • Source: University of California Cooperative Extension Publication
  • Year: 2008
  • Summary: Sample costs to produce grain corn (field corn for grain) in the southern San Joaquin Valley, California, USA, are shown in this study.
  • Authors:
    • Blackshaw, R. E.
    • Johnson, E. N.
    • Beckie, H. J.
    • Gan, Y.
  • Source: Canadian Journal of Plant Science
  • Volume: 88
  • Issue: 2
  • Year: 2008
  • Summary: Competitive crops or cultivars can be an important component of integrated weed management systems. A study was conducted from 2003 to 2006 at four sites across semiarid prairie ecoregions in Saskatchewan and Alberta to investigate the productivity and quality of canola (Brassica napus L.) and mustard cultivars under weed competition. Four open-pollinated canola cultivars, four hybrid canola cultivars, two canola-quality mustard and two oriental mustard cultivars [Brassica juncea (L.) Czern. & Coss.], and two yellow mustard (Sinapis alba L.) cultivars were grown under weedy and weed-free conditions. When combined across site-years, crop aboveground biomass at maturity and seed yield were reduced by weed interference, except for yellow and oriental mustard. However, seed oil and protein content of cultivars were not affected by weed competition. Among crop types, yellow and oriental mustard were best able to maintain biomass and seed yield under weed interference, followed in decreasing order of competitiveness by hybrid and open-pollinated canola, then canola-quality mustard.
  • Authors:
    • King, A. J.
    • Cooper, J. E.
    • Strong, W. M.
    • Dalal, R. C.
  • Source: Australian Journal of Experimental Agriculture
  • Volume: 47
  • Issue: 7
  • Year: 2007
  • Summary: No-tillage (NT) practice, where straw is retained on the soil surface, is increasingly being used in cereal cropping systems in Australia and elsewhere. Compared to conventional tillage (CT), where straw is mixed with the ploughed soil, NT practice may reduce straw decomposition, increase nitrogen immobilisation and increase organic carbon in the soil. This study examined N-15-labelled wheat straw ( stubble) decomposition in four treatments (NT v. CT, with N rates of 0 and 75 kg/ha. year) and assessed the tillage and fertiliser N effects on mineral N and organic C and N levels over a 10-year period in a field experiment. NT practice decreased the rate of straw decomposition while fertiliser N application increased it. However, there was no tillage practice x N interaction. The mean residence time of the straw N in soil was more than twice as long under the NT (1.2 years) as compared to the CT practice (0.5 years). In comparison, differences in mean residence time due to N fertiliser treatment were small. However, tillage had generally very little effect on either the amounts of mineral N at sowing or soil organic C (and N) over the study period. While application of N fertiliser increased mineral N, it had very little effect on organic C over a 10-year period. Relatively rapid decomposition of straw and short mean residence time of straw N in a Vertisol is likely to have very little long-term effect on N immobilisation and organic C level in an annual cereal cropping system in a subtropical, semiarid environment. Thus, changing the tillage practice from CT to NT may not necessitate additional N requirement unless use is made of additional stored water in the soil or mineral N loss due to increased leaching is compensated for in N supply to crops.
  • Authors:
    • Vigil, M. F.
    • Nielsen, D. C.
    • Mikha, M.
    • Benjamin, J. G.
    • Calderon, F.
    • Henry, W. B.
  • Source: Soil Science Society of America Journal
  • Volume: 71
  • Issue: 4
  • Year: 2007
  • Summary: No-till cropping systems in the semiarid West have the potential to improve soil physical properties by increasing cropping intensity and crop diversity. An investigation at Akron, Colorado, USA, compared soil conditions in winter wheat ( Triticum aestivum)-summer fallow (WF) plots with soil conditions in wheat-maize ( Zea mays)-fallow (WCF), wheat-maize-sunflower ( Helianthus annuus)-fallow (WCSF), wheat-maize-millet ( Panicum miliaceum) (WCM), and a perennial grass/legume mix. The study began in 1990. Bulk density, pore size distribution, and saturated hydraulic conductivity were measured 7, 11, and 15 years after inception. Bulk density in the grass plots decreased from 1.39 to 1.25 Mg m -3 in 15 years. Bulk density in the annually cropped plots decreased from 1.38 to 1.30 Mg m -3 during the same time period. The pore size distribution became more uniform among the cropped treatments 15 years after the start of the experiment. Saturated hydraulic conductivity increased in the grass plots from 27 to 98 mm h -1 in 15 years. Saturated hydraulic conductivity in the annually cropped plots increased from approximately 14 to approximately 35 mm h -1 during the same period. The results show that improving soil physical properties by cropping system alone may take many years. Perennial vegetation may be more effective than annually cropped systems at improving soil physical conditions because of less surface compaction from planting operations and the apparent ability of perennial root systems to create a more stable, continuous pore network.
  • Authors:
    • Perez, A.
    • Ali, M.
    • Pollack, S.
    • Lucier, G.
  • Year: 2006
  • Summary: The U.S. fruit and vegetable industry accounts for nearly a third of U.S. crop cash receipts and a fifth of U.S. agricultural exports. A variety of challenges face this complex and diverse industry in both domestic and international markets, ranging from immigration reform and its effect on labor availability to international competitiveness. The national debate on diet and health frequently focuses on the nutritional role of fruit and vegetables, and a continued emphasis on the benefits of eating produce may provide opportunities to the industry. In the domestic market, Americans are eating more fruit and vegetables than they did 20 years ago, but consumption remains below recommended levels. In terms of per capita consumption expressed on a fresh-weight basis, the top five vegetables are potatoes, tomatoes, lettuce, sweet corn, and onions while the top five fruit include oranges, grapes (including wine grapes), apples, bananas, and pineapples. The industry also faces a variety of trade-related issues, including competition with imports. During 2002-04, imports accounted for 21 percent of domestic consumption of all fresh and processed fruit and vegetables, up from 16 percent during 1992-94.
  • Authors:
    • Roose, E.
    • Mededjel, N.
    • Arabi, M.
    • Mazour, M.
    • Morsli, B.
  • Source: Soil Erosion and Carbon Dynamics
  • Year: 2006
  • Summary: Considering the effects of land use change during 1990s in the Tell mountains of northern Algeria, a research programme was developed by the Algerian INRF and the French IRD, to study the influence of land uses and cultural practices on runoff, erosion, soil fertility, and soil organic carbon (SOC) dynamics at the scale of runoff plots (100 to 220 m 2). The study included comparisons between traditional and improved land management systems for the principal soils of northern Algeria. The field experiments were conducted: (i) from 1993 to 1998 in the Beni-Chougran mountains near Mascara, in western Algeria; (ii) from 1991 to 2001 in the Tlemcen mountains in western Algeria; and (iii) from 1988 to 1992 around Medea in central Algeria. These regions are representative of the Tell mountains with regards to landscape, erosion manifestations (sheet erosion, gullies, floods and mass movements), and the various programmes of soil conservation since 1950s. The plots were set up on three soil types: (i) clayey brown Vertic soils on marl (Vertic Haploxeroll in Mascara and Tlemcen, Typic Haploxerert in Medea); (ii) brown calcareous soils on sandstone or limestone (Typic Haploxeroll in Mascara, Tlemcen and Medea); and (iii) red Fersiallitic soils on sandstone (Typic Haploxerept in Tlemcen and Medea). Data showed that at the plot scale, runoff and sheet erosion risks were generally moderate in the semiarid mountains of northern Algeria, even when the fields were cropped on steep slopes. Sediments were richer in OC than the topsoil (0-10 cm depth), and that this enrichment increased with soil surface cover (i.e., bare plots<grazed and cropped plots