• Authors:
    • Cooke, F. T.,Jr.
    • Robinson, J. R. C.
    • Martin, S. W.
    • Parvin, D.
  • Source: Crop Management
  • Issue: April
  • Year: 2005
  • Summary: This study compared conventional, reduced tillage and no-till systems for cotton, maize, soyabean and sorghum in the Mississippi Delta. Most of the necessary parameters (e.g. yields, costs, equipment, field operations) were obtained from published budgets. The conventional systems typically involved subsoiling, discing, field cultivation, hipping and in-season cultivation. The reduced tillage systems substituted herbicides for heavy pre-plant soil preparation and in-season cultivation, while no-till systems substituted herbicides for all tillage operations. A whole-farm, mixed integer programming model was developed to determine the most profitable crop/tillage combinations at different acreage sizes, assess the actual economies of size (in dollars per acre) in row crop farming, determine the number of acres required to maximize economic viability, determine the best acreage size to minimize or optimize full-time labour, and evaluate profitability trade-offs, including farm programme eligibility, under different tillage systems.
  • Authors:
    • Peterson, G. A.
    • Westfall, D. G.
    • Ortega, R. A.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 36
  • Issue: 19/20
  • Year: 2005
  • Summary: In the West Central Great Plains of the United States, no-till management has allowed for increased cropping intensity under dryland conditions. This, in turn, has affected the carbon (C) and nitrogen (N) mineralization dynamics of these systems. In this region, moisture stress increases from north to south due to an increase in evapotranspiration (ET), resulting in a climatic gradient that affects cropping system management. The objectives of this study were to determine the interaction of cropping system intensification and climatic gradient (ET) on C and N mineralization and to determine if the presence or absence of crop residue on the soil surface affects C and net N mineralization. Two cropping systems, winter wheat-fallow (WF) ( Triticum aestivium L.) and winter wheat-corn (sorghum)-millet-fallow (WCMF) [ Zea mays (L.), Sorghum bicolor (L.) Moench, Panicum milaceum (L.)] were studied at three locations across this aforementioned ET gradient. The treatments had been in place for 8 yrs prior to sampling in the study. These results showed that the more intense cropping system (WCMF) had a higher laboratory C mineralization rate at two of the three locations, which the study concluded resulted from larger residue biomass additions and larger quantities of surface residue and soil residue at these locations (Soil residue is defined as recognizable crop residue in the soil that is retained on a 0.6 mm screen). However, no differences in N mineralization occurred. This is most likely due to more N immobilization under WCMF as compared to WF. Presence or absence of crop residue on the surface of undisturbed soil cores during incubation affected potential C and net N mineralization more than either cropping system or location. Soil cores with the surface residue intact mineralized as much as 270% more C than the same soils where the surface crop residue had been removed. In laboratory studies evaluating the relative differences in cropping systems effects on C and N mineralization, the retention of crop residue on the soil surface may more accurately access the cropping system effects.
  • Authors:
    • Price, A.
    • Saini, M.
    • van Santen, E.
  • Source: 2005 Southern Conservation Tillage Systems Conference, Oral Proceedings, Clemson University
  • Year: 2005
  • Summary: An integral component of a conservation-tillage system in corn (Zea mays L.) and cotton (Gossypium hirsutum L.) is the use of a winter cover crop. A field experiment was initiated in 2002 to evaluate winter weed dynamics following various winter cover crops in both continuous cotton and a corn and cotton rotation. Winter cover crops included black oats (Avena strigosa Schreb.); two crimson clover entries (Trifolium incarnatum L.); two cultivars of forage rape (Brassica napus L. var. napus), spring and winter; oil radish (Raphanus sativus var. oleiformis Pers.); three cultivars of turnip ( Brassica rapa L. subsp. rapa); white lupin ( Lupinus albus L.); and a mixture of black oat and lupin. Two-year conservation-tillage rotational sequences included conventionally tilled continuous corn and cotton winter fallow systems as controls. The 10 conservation-tillage, winter cover-crop systems investigated were three continuous cotton systems that alternated a winter legume (lupin or clover), six cotton-corn systems, where lupin preceded cotton and radish, rape, or turnip preceded corn, and a cotton-corn system that had a lupin-black oat mixture as a winter cover crop every year. Use of lupin or 'AU Robin' clover resulted in weed biomass reduction of up to 80% and 54%, respectively, in weed biomass compared to the fallow system. The highest yielding corn-cotton conservation tillage rotation with a winter cover yielded 200 lbs/acre more that the continuous cotton winter fallow system. Continuous conventional corn with winter fallow yielded 30 bu/acre less than the highest yielding 2-yr, conservation tillage winter crop system.
  • Authors:
    • Whitehead, W. F.
    • Sainju, U. M.
    • Singh, B. P.
  • Source: Plant and Soil
  • Volume: 273
  • Issue: 1-2
  • Year: 2005
  • Summary: Soil and crop management practices may influence biomass growth and yields of cotton (Gossypium hirsutum L.) and sorghum (Sorghum bicolor L.) and sequester significant amount of atmospheric CO, in plant biomass and underlying soil, thereby helping to mitigate the undesirable effects of global warming. This study examined the effects of three tillage practices [no-till (NT), strip till (ST), and chisel till (CT)],. four cover crops [legume (hairy vetch) (Vicia villosa Roth), nonlegume (rye) (Secale cereale L), hairy vetch/rye mixture, and winter weeds or no cover crop], and three N fertilization rates (0, 60-65, and 120-130 kg N ha(-1)) on the amount of C sequestered in cotton lint (lint + seed), sorghum grain. their stalks (stems + leaves) and roots, and underlying soil from 2000 to 2002 In central Georgia, USA. A field experiment was conducted on a Dothan sandy loam (fine-loamy, kaolinitic, thermic. Plinthic Kandiudults). In 2000, C accumulation in cotton lint was greater in NT with rye or vetch/rye mixture but in stalks, it was greater in ST with vetch or vetch/rye mixture than in CT with or without cover crops. Similarly, C accumulation in lint was greater in NT with 60 kg N ha(-1) but in stalks, it was greater in ST with 60 and 120 kg N ha(-1) than in CT with 0 kg N ha(-1). In 2001, C accumulation in sorghum grains and stalks was greater in vetch and vetch/rye mixture with or without N rate than in rye without N rate. In 2002, C accumulation in cotton lint was greater in CT with or without N rate but in stalks, it was greater in ST with 60 and 120 kg N ha(-1) than in NT with or without N rate. Total C accumulation in the above- and belowground biomass in cotton ranged from 1.7 to 5.6 Mg ha(-1) and in sorghum ranged from 3.4 to 7.2 Mg ha(-1). Carbon accumulation in cotton and sorghum roots ranged from 1 to 14% of the total C accumulation in above- and belowground biomass. In NT, soil organic C at 0-10 cm depth was greater in vetch with 0 kg N ha(-1) or in vetch/rye with 120-130 kg N ha(-1) than in weeds with 0 and 60 kg N ha(-1) but at 10-30 cm, it was greater in rye with 120-130 kg N ha(-1) than in weeds with or without rate. In ST, soil organic C at 0-10 cm was greater in rye with 120-130 kg N ha(-1) than in rye, vetch, vetch/rye and weeds with 0 and 60 kg N ha(-1). Soil organic C at 0-10 and 10-30 cm was also greater in NT and ST than in CT. Since 5 to 24% of C accumulation in lint and grain were harvested, C sequestered in cotton and sorghum stalks and roots can be significant in the terrestrial ecosystem and can significantly increase C storage in the soil if these residues are left after lint or grain harvest, thereby helping to mitigate the effects of global warming. Conservation tillage, such as ST, with hairy vetch/rye mixture cover crops and 6065 kg N ha(-1) can sustain C accumulation in cotton lint and sorghum grain and increase C storage soil compared with conventional tillage, such as CT, with no cover crop and N fertilization, thereby maintaining crop yields, improving soil quality, and reducing erosion.
  • Authors:
    • Jayanthi, C.
    • Shekinah, D. E.
    • Sankaran, N.
  • Source: Journal of Sustainable Agriculture
  • Volume: 25
  • Issue: 3
  • Year: 2005
  • Summary: In a small-scale resource-poor farm, modest increments in productivity are no longer sufficient to justify the investment of scarce resources. Integrated farming systems with multiple enterprises pave the way for realizing increased productivity, profitability and sustainability in small farms of the developing countries. A study conducted at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India from July 2000 to March 2002 to optimize enterprise combination, increase employment and bring about maximum bioresource utilization and residue recycling for a 1-ha farm of the dryland tract of the western zone of Tamil Nadu compared four farming system combinations: FS 2 (crop+pigeon+goat+agroforestry+farm pond), FS 3 (crop+pigeon+buffalo+agroforestry+farm pond), and FS 4 (crop+pigeon+goat+buffalo+agroforestry+farm pond) with FS 1 (sorghum only) as the reference system. The results indicated the following: crop (0.80 ha) fertilized with buffalo manure produced on the farm, with pigeon (10 pairs on 0.01 ha), goat (5:1 female:male on 0.02 ha), buffalo (2 milking buffaloes+1 calf on 0.03 ha), agroforestry (0.10 ha) and farm pond (0.04 ha) was the profitable system enterprise that generated higher employment year-round. This system also facilitated the maximum recycling of resources and residues generated on the farm among the enterprises. The output and the waste of one enterprise served as input to another. The nutritive value of the system in terms of carbohydrate, protein and fat was also highest with this enterprise combination. Thus, FS 4 seems to be the best enterprise combination as revealed by the physical indicators. However, since the purchase and maintenance of buffalo enterprise involves higher costs, for farmers who have limited cash for investment, linkage of crop (0.80 ha) with pigeon (10 pairs on 0.01 ha), goat (5:1 female:male on 0.05 ha), agroforestry (0.10 ha) and farm pond (0.04 ha) is suggested as the alternative farming system for sustainability instead of conventional cropping alone.
  • Authors:
    • Salmond, G.
    • Swan, L.
  • Source: Australian Cottongrower
  • Volume: 26
  • Issue: 3
  • Year: 2005
  • Summary: In a field in Australia, the influence of growing different rotation crops on the level of Fusarium oxysporum f.sp. vasinfectum (Fov) in the soil was monitored over three years in a summer field crop rotation experiment. In the 2001-02 and 2002-03 seasons of the trial, the same crop was grown on the same plot. The maize plots were a forced fallow during 2002-03. In 2003-04, the entire trial was oversown with cotton cv. Nu Emerald RR. Mung bean plots were replanted with Sicot 14B six weeks later. In glasshouse pot trials, soil naturally infested with Fov was used to examine different rotation options over five crop cycles with cotton oversown across all treatments in the final cycle. In the field, significantly more cotton plants survived until maturity following a bare fallow rotation compared to cotton plants grown following either maize, cotton or sorghum crops. The greatest percentage of cotton plant death and severity of disease in cotton occurred where soyabean or mung bean crops had previously been grown. In the glasshouse, rotation cycles that included a fallow treatment either one or two crops before growing cotton generally resulted in less severe Fusarium wilt (lower MDI) compared to cycles where a fallow treatment was not included occurred early in the cycle. Crops with larger root systems (sunflower, broccoli, lucerne, maize, sorghum) had more disease (higher MDI) in the following cotton compared to crops with smaller root systems (fallow, chickpea, field pea, millet, pigeon pea), after these crops had been grown for four continuous cycles, reflecting the role of residue and organic matter in pathogen survival and disease incidence. Fov has been isolated from mature plants growing in these pot trials including sunflower (5%); maize (4%); sorghum (3%) (roots only); mung bean (24%); field pea (20%); vetch (20%); pigeon pea (12%); chickpea (4%); and lucerne (4%) (stems and roots). Further research into rotation options and the roles of crop residue, organic matter and green manuring of crops in relation to pathogen survival are discussed.
  • Authors:
    • Hanna, W. W.
    • Timper, P.
  • Source: Journal of Nematology
  • Volume: 37
  • Issue: 2
  • Year: 2005
  • Summary: Pearl millet ( Pennisetum glaucum) has potential as a grain crop for dryland crop production in the southeastern United States. Whether or not pearl millet will be compatible in rotation with cotton ( Gossypium hirsutum), corn ( Zea mays), and peanut ( Arachis hypogaea) will depend, in part, on its host status for important plant-parasitic nematodes of these crops. The pearl millet hybrid 'TifGrain 102' is resistant to both Meloidogyne incognita race 3 and M. arenaria race 1; however, its host status for other plant-parasitic nematodes was unknown. In this study, the reproduction of Belonolaimus longicaudatus, Paratrichodorus minor, Pratylenchus brachyurus, and Meloidogyne javanica race 3 on pearl millet ('HGM-100' and TifGrain 102) was compared relative to cotton, corn, and peanut. Separate greenhouse experiments were conducted for each nematode species. Reproduction of B. longicaudatus was lower on peanut and the two millet hybrids than on cotton and corn. Reproduction of P. minor was lower on peanut and TifGrain 102 than on cotton, corn, and HGM-100. Reproduction of P. brachyurus was lower on both millet hybrids than on cotton, corn, and peanut. Reproduction of M. javanica race 3 was greater on peanut than on the two millet hybrids and corn. Cotton was a nonhost. TifGrain 102 was more resistant than HGM-100 to reproduction of B. longicaudatus, P. minor, and M. javanica. Our results demonstrated that TifGrain 102 was a poor host for B. longicaudatus and P. brachyurus (Rf
  • Authors:
    • Ellis-Jones, J.
    • Tripathi, B. P.
  • Source: Renewable Natural Resources Management for Mountain Communities
  • Year: 2005
  • Summary: Agriculture is the main source of livelihood for most people in hillside areas of Nepal, and soil fertility is largely maintained through the use of organic manure. Discussions with farmers indicated five principal soil fertility management practices (manure, chemical fertilizer, compost based on leaf litters, growing legume crops, and in-situ manuring). Farmers identified five soil productivity indicators (crop productivity, soil characteristics (particularly soil colour), management requirement, species of weeds, diseases, and pests, and termites). Historical trends (increasing crop intensification, decreasing livestock numbers, increasing use of chemical fertilizers, reduced labour availability, and change in the climate over the last 30-40 years) showed a decline in soil productivity. Scored causal diagrams on soil fertility drawn from focus group discussions indicated that the primary causes of declining soil fertility and crop productivity are a decrease in available manure, increased cropping intensity, low use of chemical fertilizers, and change in climate. Scientific evaluation confirmed that altitude, farming system, and land types affected the availability of soil nutrients. Organic C, total N, available P and exchangeable K increased in less intensive farming systems, which were at higher altitudes. These nutrients as well as available Fe, Mn, and B in soil significantly increased in rainfed upland (bari) compared with irrigated lowland (khet). Covering manure with black plastic sheets resulted in faster decomposition as well as increased total N and exchangeable K. Covered manure applied to summer rainfed maize and upland rice as well as irrigated lowland spring maize increased grain and straw yields between 13 and 36% when compared with uncovered manure. Both farmers' indigenous knowledge and their criteria were as useful as scientific evaluation in assessing soil fertility improvements. Therefore, farmers' knowledge and criteria should be considered when monitoring soil fertility and crop productivity in farmer trials.
  • Authors:
    • Scott, A. W.,Jr.
    • Westphal, A.
  • Source: Crop Science
  • Volume: 45
  • Issue: 1
  • Year: 2005
  • Summary: Rotylenchulus reniformis Linford & Oliveira is increasing in incidence in cotton-growing areas throughout the southern USA east of New Mexico. Cotton (Gossypium hirsutum L.) cultivars resistant to R. reniformis are currently unavailable. Management depends on a crop sequence with nonhosts of the nematode. In South Texas, the sequence of cotton with grain sorghum [ Sorghum bicolor (L.) Moench] or corn ( Zea mays L.) has become a standard practice. To improve farm efficiency, the implementation of rotation crops that are economically superior to grain sorghum is desirable. Eighteen cultivars of soybean [ Glycine max (L.) Merr.] were tested in nonfumigated and in fumigated sandy loam soil infested with R. reniformis to evaluate nematode resistance of soybean under field conditions. Shank application of 1,3-dichloropropene at a 38-cm depth reduced R. reniformis population densities at the 15- to 60-cm depth compared with preseason counts. The effect of each soybean cultivar on the growth and yield of a subsequent cotton crop was compared with the impact of grain sorghum and fallow. High-yielding cultivars of soybean (HY574, Padre, DP7375RR, and NK83-30) with reniform nematode-suppressing potential were identified among cultivars within maturity groups 5, 6, 7, and 8. In contrast, cotton yields following the susceptible cultivars Santa Rosa-R, Vernal, and DP6880RR were on average 25% lower than those following grain sorghum. The enrichment of cotton sequences with reniform nematode-resistant soybean cultivars is viable when the proper cultivars are chosen, whereas the use of reniform nematode-susceptible soybean cultivars is discouraged. The effective use of R. reniformis-resistant soybean cultivars to manage R. reniformis in cotton will depend on a number of additional economic parameters not studied in these experiments.
  • Authors:
    • Prado A., R. del
    • Diaz S., J.
    • Espinoza N., N.
  • Source: XVII Congreso de la Asociación Latinoamericana de Malezas (ALAM) I Congreso Iberoamericano de Ciencia de las Malezas, IV Congreso Nacional de Ciencia de Malezas, Matanzas, Cuba, 8 al 11 de noviembre del 2005, pp. 326
  • Year: 2005
  • Summary: Eight biotypes of herbicide-resistant weeds have been described in Chile. All belong to grass weeds, specifically wild oat ( Avena fatua), ryegrass ( Lolium rigidum), Italian ryegrass ( L. multiflorum) and crested dogtailgrass ( Cynosurus echinatus), which are the most common in the main wheat, barley, oats, lupin and canola producing area (36degreesS to 39degreesS). The biotypes have shown resistance to ACCasa, ALS and EPSP inhibitors. Most biotypes have appeared in farm fields subjected to intensive land use, with annual crops, with a trend to wheat monoculture in some cases, and with intense use of no-till and herbicides with similar mode of action. Herbicides most frequently used have been glyphosate (EPSP), diclofop-methyl and clodinafop-propargyl (ACCasa). Cross-resistance to ACCasa was found in some biotypes of wild oat and ryegrass, with greater resistance to aryloxyphenoxypropionates than to cyclohexanediones. All ACCasaresistant biotypes were susceptible to iodosulfuron and flucarbazone Na (ALS). These two herbicides are recommended for wheat and began to be used just recently in the country. Two biotypes of Italian ryegrass were found resistant to glyphosate. One of these biotypes showed, in addition, resistance to ALS; that is to say, showed multiple resistance. Also the crested dogtailgrass biotype showed multiple resistance to ACCasa and ALS.