• Authors:
    • Bauer, P. J.
    • Watts, D. W.
    • Frederick, J. R.
    • Novak, J. M.
  • Source: Soil Science Society of America Journal
  • Volume: 73
  • Issue: 2
  • Year: 2009
  • Summary: Long-term disk tillage (DT) for cotton (Gossypium hirsutum L.) production in the southeastern U.S. Coastal Plain has resulted in soil organic C (SOC) content reductions. Conservation tillage (CT) management in some studies can rebuild SOC levels. A field study, with two adjacent 3.5-ha fields, both containing soil series formed in upland and depressional areas, was conducted using a 6-yr rotation of corn (Zea mays L.) and cotton to determine the CT and DT effects on SOC contents and residue characteristics returned to the soil. Annual soil samples were collected from 50 locations per field at 0- to 3- and 3- to 15-cm. After 6 yr under CT, residue accumulation promoted a significant SOC increase in the 0- to 3-cm depth in the upland soil series (about 0.7 Mg SOC ha(-1)). The lack of residue mixing in the 3- to 15-cm depth in upland Soils under CT however, resulted in a significant SOC content decline at this depth (1.25-2.51 Mg SOC ha(-1)). There was no significant SOC content change in soils under CT formed in depressional areas or in all soils under DT During 6 yr, 14.8 Mg ha(-1) of organic C from both corn and cotton residues was returned to Soils under CT but <4% was incorporated into the SOC pool. Levels of SOC in sandy upland soils can be increased at the surface after 6 yr of CT under a corn and cotton rotation, with the increase coming at the expense of an SOC decline at a deeper topsoil depth.
  • Authors:
    • Grau, R.
    • Baptista, S.
    • Birkenholtz, T.
    • Lambin, E. F.
    • Ickowitz, A.
    • Hecht, S.
    • Geoghegan, J.
    • Lawrence, D.
    • DeFries, R. S.
    • Turner, B. L.
    • Uriarte ,M.
    • Schneider ,L.
    • Rudel, T. K.
  • Source: Proceedings of the National Academy of Sciences of the United States of America
  • Volume: 106
  • Issue: 49
  • Year: 2009
  • Summary: Does the intensification of agriculture reduce cultivated areas and, in so doing, spare some lands by concentrating production on other lands? Such sparing is important for many reasons, among them the enhanced abilities of released lands to sequester carbon and provide other environmental services. Difficulties measuring the extent of spared land make it impossible to investigate fully the hypothesized causal chain from agricultural intensification to declines in cultivated areas and then to increases in spared land. We analyze the historical circumstances in which rising yields have been accompanied by declines in cultivated areas, thereby leading to land-sparing. We use national-level United Nations Food and Agricultural Organization data on trends in cropland from 1970-2005, with particular emphasis on the 1990-2005 period, for 10 major crop types. Cropland has increased more slowly than population during this period, but paired increases in yields and declines in cropland occurred infrequently, both globally and nationally. Agricultural intensification was not generally accompanied by decline or stasis in cropland area at a national scale during this time period, except in countries with grain imports and conservation set-aside programs. Future projections of cropland abandonment and ensuing environmental services cannot be assumed without explicit policy intervention.
  • Authors:
    • Weller, S. C.
    • Kruger, G. R.
    • Davis, V. M.
    • Johnson, W. G.
  • Source: European Journal of Agronomy
  • Volume: 31
  • Issue: 3
  • Year: 2009
  • Summary: Glyphosate-resistant (GR) crops have facilitated increases in conservation tillage production practices and simplified weed control in GR corn, soybean, canola and cotton. Increased reliance on glyphosate, many times as the only active ingredient used, has resulted in weed species shifts and the evolution of weed populations resistant to glyphosate. However, weed shifts and the evolution of herbicide resistance are not new in regard to glyphosate use. Similar effects have been documented to many other historically important weed control advancements for agricultural crop production. GR crop technology was developed to utilize glyphosate for postemergence weed control and industry scientists suggested that there was little fear of weed shifts and resistance evolution due to the broad spectrum of weeds controlled by glyphosate. However, over the last decade, the most problematic weeds in agronomic cropping systems have shifted away from perennial grass and perennial broadleaf weeds to primarily annual broadleaf weeds. The evolution of several GR annual broadleaf weeds in GR cropping systems has been documented, and glyphosate resistance mechanisms in weeds are currently poorly understood.
  • Authors:
    • Horwath, W.
    • Kallenbach, C.
    • Assa, J.
    • Burger, M.
  • Year: 2009
  • Authors:
    • Benbrook, C.
  • Source: Critical Issue Report: The First Thirteen Years
  • Year: 2009
  • Summary: Th is report explores the impact of the adoption of genetically engineered (GE) corn, soybean, and cotton on pesticide use in the United States, drawing principally on data from the United States Department of Agriculture. Th e most striking finding is that GE crops have been responsible for an increase of 383 million pounds of herbicide use in the U.S. over the first 13 years of commercial use of GE crops (1996-2008).
  • Authors:
    • Sanjay, K.
    • Sharma, S.
    • Kaushik, V.
  • Source: Journal of Environmental Research and Development
  • Volume: 4
  • Issue: 4
  • Year: 2009
  • Summary: Suitable to environment or eco-friendly means not harmful to our system of environment i.e. not harmful to land, air etc. Presently, due to agriculture a lot of pollutants are added day by day in our environment. Because of these pollutants, the soil fertility is decreasing, the fear of disease in living beings are increasing, a lot of poisonous chemicals and gases prevails in the environment. There is a great need to the use of such a cropping system which is suitable to environment i.e Eco-friendly system of cropping. The Eco-friendliness of cropping system may be viewed from two different angles i.e systems which help in soil and water conservation and system which reduce the use of pesticides, insecticides, herbicides, organic fertilizers. As far as the pesticides use is concerned at national level, it is a still for below the alarming proportions. Inclusion of such crops in the cropping systems in problem areas can play a significant role in minimizing the use of agro-chemicals in the crop production. Insecticides or fungicides use can also be minimized to a considerable extent through cropping system approach. It has been reported that sorghum ear-head fly damage is extremely rare where pigeon pea is planted in alternate rows. Intercropping of coriander in autumn planted sugarcane prevent top borer in sugarcane Sorghum helepense ( L) pers (Tohangen grass) becomes predominant weed in continuous maize cultivation but can be controlled by rotating with cotton. Adoption of sugarcane wheat system in place of rice-wheat decreases philaries minor infestation to almost negligible level which is otherwise not achieved through herbicides. In maize-potato cropping system raising of pearl millet for green fodder or sesamum for green manure during summer was also found advantageous in reducing Cyprus rotundas in succeeding crop of maize and potato. Position of ground water owing to leaching of nitrates is a selectively new concern in India. Because usage of N-fertilizer is low in India, nitrate is not likely to pose serious problems in most farming situations. Choice of appropriate system and management practices helped minimizing nitrate leaching besides improving N-use efficiency.
  • Authors:
    • Gajbhiye, K. S.
    • Ray, S. K.
    • Prasad, J.
    • Singh, S. R.
  • Source: Agropedology
  • Volume: 19
  • Issue: 2
  • Year: 2009
  • Summary: Detailed soil survey of Selsura KVK research farm of Dr. P.D.K.V., Akola in Wardha district, Maharashtra was carried out using 1:6000 scale cadastral map. There were nine soil series and thirteen mapping units. The soils were very dark gray to very dark grayish brown in hue 10YR, calcareous and clayey but differed in depth and are classified under Entisols, Inceptisols and Vertisols. In general, pH (8.0-9.2) increased with depth whereas reverse trend was observed for organic carbon. Soils of Selsura-1 are prone to sodicity problems. DTPA-Zn and Fe were deficient in these soils but DPTA-Mn and Cu were optimum. The mapping units were grouped under II to IV land capability classes and 2 to 4 land irrigability classes. Except soils of Selsura-7 series (very shallow), others are moderately or marginally suitable for one or more commonly growing rainfed kharif crops viz. cotton, sorghum, pigeonpea, soybean and groundnut.
  • Authors:
    • Kumar, S.
    • Thakral, S. K.
    • Kadian, V. S.
  • Source: Haryana Journal of Agronomy
  • Volume: 25
  • Issue: 1/2
  • Year: 2009
  • Summary: A field experiment was carried out from 2003-04 to 2005-06 at Agronomy Research Area of CCS Haryana Agricultural University, Hisar to find out the profitable crop rotation in south-west Haryana. In the rotation the different kharif season crops i. e. cotton ( Gossypium hirsutum L.), soybean [ Glycine max (L.) Merrill], mungbean [ Vigna radiata (L.) Wilczek], pearl millet [ Pennisetum glaucum (L.) Emend. Stuntz] and sorghum [ Sorghum bicolor (L.) Moench] were grown with rotation in rabi season crops i. e. wheat [ Triticum aestivum (L.) Emend. Fiori & Paol.], barley ( Hordeum vulgare L.), chickpea ( Cicer arietinum L.) and raya ( Brassica juncea L.). Based on the mean of three-year rotation, cotton-based rotation registered maximum land use efficiency, whereas it was lowest in sorghum-based rotations. Among the different crop rotations, cotton-barley and soybean-wheat were found profitable based on the net returns and B:C ratio. Pearl millet-based crop rotations were found remunerative as compared to other kharif season crops.
  • Authors:
    • Jajoo, S. B.
    • Kamble, P. O.
    • Shinde, K. J.
  • Source: Green Farming
  • Volume: 13
  • Issue: 1 (Special 1)
  • Year: 2009
  • Summary: A study was conducted to suggest optimal resources allocation for crop plan to net benefit maximization using linear programming model for Akola district in Maharashtra state. Resources management plan was developed with allocation of land and water for different crop activities to maximize the net return taking into account land capability classification, availability of water in different season, crop water requirements, food requirement and affinity towards the crops of the peoples in district. In existing crop plan during kharif season major area is under cotton (43.45%) followed by jowar (17%) whereas in proposed optimal crop plan without capital constraints major area was allocated under soybean (30%), cotton+tur (20%) of the total cultivable area of the district. In rabi major area in existing is under gram (5.2%) whereas in proposed plan area is allocated to wheat (20%), gram (20%). In existing summer area is 0.18% and annual was nil whereas in proposed plan is 3% and 4.13% respectively. In existing gross investment and net return per hectare was 10341 and 5203 Rs/ha whereas in proposed plan is 14864 and 8833 Rs/ha. In proposed plan net return per hectare increases by Rs. 3630.
  • Authors:
    • Bernards, M. L.
    • Wilson, R. G.
    • Jordan, D. L.
    • Wilcut, J. W.
    • Shaw, D. R.
    • Owen, M. D. K.
    • Weller, S. C.
    • Johnson, W. G.
    • Kruger, G. R.
    • Young, B. G.
  • Source: Weed Technology
  • Volume: 23
  • Issue: 1
  • Year: 2009
  • Summary: Corn and soybean growers in Illinois, Indiana, Iowa, Mississippi, Nebraska, and North Carolina, as well as cotton growers in Mississippi and North Carolina, were surveyed about their views on changes in problematic weeds and weed pressure in cropping systems based on a glyphosate-resistant (GR) crop. No growers using a GR cropping system for more than 5 yr reported heavy weed pressure. Over all cropping systems investigated (continuous GR soybean, continuous GR cotton, GR corn/GR soybean, GR soybean/non-GR crop, and GR corn/non-GR crop), 0 to 7% of survey respondents reported greater weed pressure after implementing rotations using GR crops, whereas 31 to 57% felt weed pressure was similar and 36 to 70% indicated that weed pressure was less. Pigweed, morningglory, johnsongrass, ragweed, foxtail, and velvetleaf were mentioned as their most problematic weeds, depending on the state and cropping system. Systems using GR crops improved weed management compared with the technologies used before the adoption of GR crops. However, the long-term success of managing problematic weeds in GR cropping systems will require the development of multifaceted integrated weed management programs that include glyphosate as well as other weed management tactics.