• Authors:
    • Egli, D. B.
  • Source: Field Crops Research
  • Volume: 106
  • Issue: 1
  • Year: 2008
  • Summary: The increases in crop yield that played an important role in maintaining adequate food supplies in the past may not continue in the future. Soybean ( Glycine max L. Merrill) county yield trends (1972-2003) were examined for evidence of plateaus using data (National Agricultural Statistics Service) for 162 counties (215 data sets) in six production systems [Iowa, Nebraska (irrigated and non-irrigated), Kentucky and Arkansas (irrigated and non-irrigated)] representing a range in yield potential. Average yield (1999-2003) was highest in irrigated production in Nebraska (3403 kg ha -1) and lowest in non-irrigated areas in Arkansas (1482 kg ha -1). Average yield in the highest yielding county in each system was 31-88% higher than the lowest. Linear regression of yield versus time was significant ( P=0.05) in 169 data sets and a linear-plateau model reached convergence (with the intersection point in the mid-1990s) in 35 of these data sets, but it was significantly ( P=0.10) better in only three data sets (
  • Authors:
    • Correia, M. E. F.
    • Mercante, F. M.
    • Silva, R. F. da
    • Aquino, A. M. de
    • Guimaraes, M. de F.
    • Lavelle, P.
  • Source: European Journal of Soil Biology
  • Volume: 44
  • Issue: 2
  • Year: 2008
  • Summary: This work was aimed at evaluating the invertebrate macrofauna community in the soil, by means of its abundance and richness of groups under different plant covers in the no-till system. Evaluations were performed at the experimental field of Embrapa Agropecuaria Oeste, in the municipal district of Dourados-MS, on a Typic Hapludox under conventional, no-till, and natural systems. Samplings were performed in December 2000, June 2001, January 2002, and June 2002. Five soil monoliths measuring 0.25*0.25 m width and 0.30 m depth were sampled along a transect. Turnip residues before a corn crop (turnip/corn) and soybean residues before wheat and turnip crops (soybean/wheat and soybean/turnip) provided positive effects on the density and diversity of the edaphic macrofauna community.
  • Authors:
    • Graef, G. L.
    • Elmore, R. W.
    • Cassman, K. G.
    • Dobermann, A.
    • Setiyono, T. D.
    • Bastidas, A. M.
    • Specht, J . E.
  • Source: Crop Science
  • Volume: 48
  • Issue: 2
  • Year: 2008
  • Summary: The sensitivity of soybean [ Glycine max (L.) Merr.] main stem node accrual to ambient temperature has been documented in greenhouse-grown plants but not with field-grown plants in the north-central United States. Biweekly V-node and R-stage, stem node number, internode length, and other traits were quantified in an irrigated split-plot, four-replicate, randomized complete block experiment conducted in Lincoln, NE, in 2003-2004. Main plots were early-, mid-, late-May, and mid-June sowing dates. Subplots were 14 cultivars of maturity groups 3.0 to 3.9. Node appearance was surprisingly linear from V1 to R5, despite the large increase in daily temperature from early May (10-15degreesC) to July (20-25degreesC). The 2003 and 2004 May planting date regressions exhibited near-identical slopes of 0.27 node d -1 (i.e., one node every 3.7 d). Cold-induced delays in germination and emergence did delay the V1 date (relative to planting date), so the primary effect of temperature was the V1 start date of linearity in node appearance. With one exception, earlier sowings led to more nodes (earlier V1 start dates) but also resulted in shorter internodes at nodes 3 to 9 (cooler coincident temperatures), thereby generating a curved response of plant height to delayed plantings. Delaying planting after 1 May led to significant linear seed yield declines of 17 kg ha -1 d -1 in 2003 and 43 kg ha -1 d -1 in 2004, denoting the importance of early planting for capturing the yield potential available in soybean production, when moisture supply is not limiting.
  • Authors:
    • Rao, K. C.
    • Bharathi, V.
    • Reddy, L. K.
  • Source: International Journal of Agricultural Sciences
  • Volume: 4
  • Issue: 2
  • Year: 2008
  • Summary: Plant root exudates are known to affect survival, reproduction and development of various microorganisms in soil through extremely complex phenomenon. Saprophytic and pathogenic activities such as competition and antibiosis of the root microflora are mediated by exudates. An analysis of the effect of different crop root exudates such as groundnut, castor, soybean, sunflower, maize, green gram, hybrid sorghum and resistant pigeon pea revealed high inhibitory effect on conidial germination and radial growth of fusarium udum. In contrast, the root exudates of local sorghum varieties had less influence on the radial growth of antagonistic fungi viz., Penicillium sp., Trichoderma sp. Aspergillus sp. in the increasing order (6.8, 9.8 and 10 per cent), in spite of promoting germination and radial growth of the wilt pathogen Fusarium udum. However, root exudates of some crops such as groundnut, cotton, hybrid sorghum and resistant pipeaonpea had stimulatory effect on antagonistic fungi such as Aspergillus sp. Pencillium sp. and Trichoderma sp. in the range of 39.8 to 47.5 per cent. Root exudates of cotton were, however, found to promote both the wilt pathogen, as well as antagonistic fungi. Groundnut and castor exudates were found to be at par with each other in the promotion of radial growth of antagonists. Identification of such biochemical compounds in the crop root exudates responsible for inhibition or stimulation of the fungi would be more useful.
  • Authors:
    • Payero, J. O.
    • Schneekloth, J. P.
    • Klocke, N. L.
  • Source: Transactions of the ASABE
  • Volume: 50
  • Issue: 6
  • Year: 2007
  • Summary: Dwindling water supplies for irrigation are prompting alternative management choices by irrigators. Limited irrigation, where less water is applied than full crop demand, may be a viable approach. Application of limited irrigation to maize ( Zea mays) was examined in a study conducted at the West Central Research and Extension Centre of the University of Nebraska-Lincoln at North Platte, Nebraska, USA. Maize was grown in crop rotations with dryland, limited irrigation, or full irrigation management from 1985 to 1999. Crop rotations included maize following maize (continuous maize), maize following wheat ( Triticum aestivum), followed by soyabean ( Glycine max) (wheat-maize-soyabean), and maize following soyabean (maize-soyabean). Full irrigation was managed to meet crop evapotranspiration requirements (ETc). Limited irrigation was managed with a seasonal target of no more than 150 mm applied. Precipitation patterns influenced the outcomes of measured parameters. Dryland yields had the most variation, while fully irrigated yields varied the least. Limited irrigation yields were 80 to 90% of fully irrigated yields, but the limited irrigation plots received about half the applied water. Grain yields were significantly different among irrigation treatments. Yields were not significantly different among rotation treatments for all years and water treatments. For soil water parameters, more statistical differences were detected among the water management treatments than among the crop rotation treatments. Economic projections of these management practices showed that full irrigation produced the most income if water was available. Limited irrigation increased income significantly from dryland management.
  • Authors:
    • Srinivasarao, C.
    • Vittal, K.
  • Source: Indian Journal of Fertilisers
  • Volume: 3
  • Issue: 5
  • Year: 2007
  • Summary: Soil samples from 21 locations of the All India Coordinated Research Project for Dryland Agriculture (AICRPDA) were characterized for organic carbon and availability of nutrients such as nitrogen, phosphorus, potassium, sulfur, Ca, Mg, Zn, Fe, Mn, Cu and B. These twenty one locations cover agro-ecological regions from 2.3 to 12.3, semiarid, and sub-humid climate, soils examined were Vertisols, Vertic sub-groups, Affisols, Inceptisols and Aridisols from different Indian states including Uttar Pradesh, Punjab, Jammu and Kashmir, Orissa, Jharkhand, Andhra Pradesh, Karnataka, Gujarat, Madhya Pradesh, Maharshtra, Tamil Nadu, Rajasthan, and Haryana. Representative soil profile samples from following production systems were collected: upland rice, groundnut, soyabeans, cotton,Rabi sorghum, pearlmillet, fingermillet and maize-based system. Rainfall ranged from 412 to 1378 mm among locations. Various physico-chemical properties of the 21 profiles indicated that most of the locations were low in organic carbon showing less than 0.5% organic C. Clay content varied widely among soil types. Low organic matter in these soils was one of the important factors contributing to low soil fertility. Except few locations, most of the soils were low in available N. Available P varied from low to very high. Available K and sulfur varied from low to high. Available Zn was below critical limit in Rajkot, Anatapur, Rewa, Akola, Bellary, Bijapur and Solapur, Agra, S.K. Nagar, Arjia, Hoshiarpur and Rakh Dhiansar. Iron was deficient in Rajkot, Bellary and Bijapur. Surface layers of several profiles were deficient in available Ca (<1.5 me 100/g) such as Phulbani, Anantapur, S.K. Nagar and Bangalore. Surface layers of soils at Phulbani, Ranchi, Anantapur, Agra, Hisar, S.K. Nagar, Bangalore, Arjia, Hoshiarpur and Rakh Dhiansar were Mg deficient (<1.0 me 100/g). Out of the 21 locations, 11 were boron deficient. Except Indore, all other soils were multinutrient deficient. Results suggest that dryland soils are multinutrient deficient, thus proper nutrient management strategies and soil water conservation practices in dryland agriculture are needed.
  • Authors:
    • Babu, C.
    • Sureshkumar, P.
    • Sivakumar, S.
    • Chandaragiri, K.
    • Thirukumaran, K.
    • Ramesh, S.
    • Umashankar, R.
  • Source: Journal of Ecobiology
  • Volume: 19
  • Issue: 1
  • Year: 2007
  • Summary: Field experiments were carried out at the Tamil Nadu Agricultural University farm, Coimbatore, India, during north-east monsoon seasons of 2000-01 and 2001-02 to design a viable farming system by linking the crop and animal components viz., goat, rabbit and pigeon to sustain crop productivity and profitability and increasing the employment opportunity of dry land farmers. Among the different crops in the farming systems, pearl millet (cumbu) + soyabean grain, maize + cowpea fodder and Cenchrus ciliaris + Stylosanthes scabra fodder system with goat, rabbit and pigeon system were higher economic parameters in the second year than the first year. The economics of the integrated farming system revealed the superiority of pearl millet + soyabean grain, maize + cowpea fodder and C. ciliaris + S. scabra fodder with goat, rabbit and pigeon system in terms of higher total returns of Rs. 162 616 and 206 942, net returns of Rs. 80 924 and 125 250, benefit-cost ratio of 1.99 and 2.53 for every rupee invested and the per day returns (Rs.222 and 343) compared to other systems in first and second year, respectively. It also generated maximum employment opportunity of 490 man-days per year compared to other systems.
  • Authors:
    • Karunanithi, S.
    • Sureshkumar, P.
    • Umashankar, R.
    • Sivakumar, S.
    • Chandaragiri, K.
    • Thirukumaran, K.
    • Ramesh, S.
    • Babu, C.
  • Source: Journal of Ecobiology
  • Volume: 19
  • Issue: 3
  • Year: 2007
  • Summary: Field experiments were carried out at Tamil Nadu Agricultural University farm, Coimbatore (India) during north-east monsoon seasons of 2000-01 and 2001-02, to design a viable farming system by linking the crop and animal components, viz., goat, rabbit and pigeon to sustain the production and productivity of dry land through effective recycling of organic wastes. Results revealed that among the different crops in the farming systems, pearl millet (cumbu)+soyabean grain, maize+cowpea fodder and Cenchrus ciliaris+ Stylosanthes scabra fodder system added higher crop residues of 4250 and 5360 kg ha -1 in the first and second year, respectively. The cumbu+soyabean grain, maize+cowpea fodder and Cenchrus ciliaris+ Stylosanthes scabra fodder system added higher NPK through the residues addition in both the years by recording 31.0, 8.9 and 45.9 kg ha -1; and 39.1, 11.3 and 57.9 kg ha -1 of NPK for the first and second year, respectively. The conventional system (sorghum+cowpea grain) recorded the least amount of NPK addition through the crop residues in both the years. The total organic residues added by the crops+goat+rabbit+pigeon farming system were higher than other system in both the years (9527 and 8170 kg ha -1) and crop+goat+ rabbit+pigeon system added higher total NPK in both the years.
  • Authors:
    • Carvalho, P. C. de F.
    • Cassol, L. C.
    • Anghinoni, I.
    • Flores, J. P. C.
    • Leite, J. G. dal B.
    • Fraga, T. I.
  • Source: REVISTA BRASILEIRA DE CIENCIA DO SOLO
  • Volume: 31
  • Issue: 4
  • Year: 2007
  • Summary: The integration of farming and cattle production activities in no-tillage system areas with winter cover crops can be an income supplement for summer grain farmers. However, many of them are afraid of adopting this integration system because of possible negative effects of animal treading on soil attributes, mainly of those related to soil compaction. This study was conducted: (1) to determine the alterations in the soil physical attributes promoted by animal treading; and (2) to verify if the alterations in soil attributes due to animal treading affect soyabean establishment and grain yield. The experiment was carried out with a Rhodic Hapludox (Oxisol), under black oat [ Avena nuda] + ryegrass [ Lolium] pasture grazed at different heights (10, 20, 30 and 40 cm) and an ungrazed area. After one cycle of animal treading, there were no significant modifications in soil bulk density, porosity and compressibility at different grazing heights. However, soil density and compressibility were higher and the porosity lower in the grazed plots. The soyabean population and grain yield were not affected by modifications in the soil physical attributes.
  • Authors:
    • Souza, R. A.
    • Crispino, C. C.
    • Franchini, J. C.
    • Torres, E.
    • Hungria, M.
  • Source: Soil & Tillage Research
  • Volume: 92
  • Issue: 1/2
  • Year: 2007
  • Summary: The objective of this work was to identify soil parameters potentially useful to monitor soil quality under different soil management and crop rotation systems. Microbiological and chemical parameters were evaluated in a field experiment in the State of Parana, southern Brazil, in response to soil management [no-tillage (NT) and conventional tillage (CT)] and crop rotation [including grain (soybean, S; maize, M; wheat, W) and legume (lupin, L.) and non-legume (oat, O) covers] systems. Three crop rotation systems were evaluated: (1) (O/M/O/S/W/S/L/M/O/S), (2) (O/S/L/M/O/S/W/S/L/M), and (3) (O/S/W/S/L/M/O/M/W/M), and soil parameters were monitored after the fifth year. Before ploughing, CO 2-emission rates were similar in NT and CT soils, but plough increased it by an average of 57%. Carbon dioxide emission was 13% higher with lupin residues than with wheat straw; decomposition rates were rapid with both soil management systems. Amounts of microbial biomass carbon and nitrogen (MB-C and MB-N, respectively) were 80 and 104% higher in NT than in CT, respectively; however, in general these parameters were not affected by crop rotation. Efficiency of the microbial community was significantly higher in NT: metabolic quotient ( qCO 2) was 55% lower than in CT. Soluble C and N levels were 37 and 24% greater in NT than in CT, respectively, with no effects of crop rotation. Furthermore, ratios of soluble C and N contents to MB-C and MB-N were consistently lower in NT, indicating higher immobilization of C and N per unit of MB. The decrease in qCO 2 and the increase in MB-C under NT allowed enhancements in soil C stocks, such that in the 0-40 cm profile, a gain of 2500 kg of C ha -1 was observed in relation to CT. Carbon stocks also varied with crop rotation, with net changes at 0-40 cm of 726, 1167 and -394 kg C ha -1 year, in rotations 1, 2 and 3, respectively. Similar results were obtained for the N stocks, with 410 kg N ha -1 gained in NT, while crop rotations 1, 2 and 3 accumulated 71, 137 and 37 kg of N ha -1 year -1, respectively. On average, microbial biomass corresponded to 2.4 and 1.7% of the total soil C, and 5.2 and 3.2% of the N in NT and CT systems, respectively. Soil management was the main factor affecting soil C and N levels, but enhancement also resulted from the ratios of legumes and non-legumes in the rotations. The results emphasize the importance of microorganisms as reservoirs of C and N in tropical soils. Furthermore, the parameters associated with microbiological activity were more responsive to soil management and crop rotation effects than were total stocks of C and N, demonstrating their usefulness as indicators of soil quality in the tropics.