• 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:
    • Oenema, O.
    • Perdok, U. D.
    • Hoogmoed, W. B.
    • Cai, D.
    • Wang, X.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 79
  • Issue: 1
  • Year: 2007
  • Summary: The rapidly increasing population and associated quest for food and feed in China has led to increased soil cultivation and nitrogen (N) fertilizer use, and as a consequence to increased wind erosion and unbalanced crop nutrition. In the study presented here, we explored the long-term effects of various combinations of maize stover, cattle manure and nitrogen (N) and phosphorus (P) fertilizer applications on maize ( Zea mays L.) yield and nutrient and water use efficiencies under reduced tillage practices. In a companion paper, we present the effects on nutrient balances and soil fertility characteristics. The ongoing factorial field trial was conducted at Shouyang Dryland Farming Experimental Station in northern China from 1993 onwards. The incomplete, determinant-optimal design comprised 12 treatments, including a control treatment, in duplicate. Grain yields and N, P, and potassium (K) uptakes and N, P and K use efficiencies were greatly influenced by the amount of rain during the growing season (GSR), and by soil water at sowing (SWS). There were highly significant interactions between GSR and added stover and manure, expressed in complex annual variations in grain yield and N, P and K use efficiencies. Annual mean grain yields ranged from 3,000 kg ha -1 to 10,000 kg ha -1 and treatment mean yields from 4,500 kg ha -1 to 7,000 kg ha -1. Balanced combination of stover (3,000-6,000 kg), manure (1,500-6,000 kg) and N fertilizer (105 kg) gave the highest yield. Stover and manure were important for supplying K, but the effects differed greatly between years. Overall mean N recovery efficiency (NRE) ranged from 28% to 54%, depending on N source. NRE in wet years ranged from 50% to 90%. In conclusion, balanced combinations of stover, manure and NP fertilizer gave the highest yield and NRE. Reduced tillage with adding stover and manure in autumn prior to ploughing is effective in minimizing labour requirement and wind erosion. The potentials of split applications of N fertilizer, targeted to the need of the growing crop (response farming), should be explored to further increase the N use efficiency.
  • Authors:
    • Qin, Y.
    • Li Fengmin
    • Li, Y.
    • Xiang, S.
    • Cao, X.
    • Wu, T.
  • Source: Dryland crop production: technology breakthroughs and study cases
  • Year: 2007
  • Summary: Fertilization according to soil hydraulic conditions, fertilization in balance of nutrition and fertilization with nutrient use efficiency and sustainability are reestablished as the principles of fertility management in dryland area on the Loess Plateau according to the natural conditions and soil properties. Corresponding techniques to the principles are reviewed and represented in the paper.
  • Authors:
    • Yang, W.
    • Wu, Y.
    • Tu, X.
    • Tu, N.
    • Zhou, W.
    • Yi, Z.
  • Source: Research of Agricultural Modernization
  • Volume: 28
  • Issue: 4
  • Year: 2007
  • Summary: The effects of tillage and no-tillage, and different rates of straw mulching (without, half and full) on soil nutrient content and drought resistance of maize on dry land in Hunan Province (China) were determined. It was found that straw mulching promoted growth and development of maize in normal year (2004) but did not reduce the effect of high temperature and drought and prolonged filling stage 2-4 d in high temperature and drought year (2005). Cultivation measures slightly affected the growth and development of maize. No-tillage prolonged growth duration for around 2 days under high temperature and drought condition. Straw mulching increased plant height, leaf area, dry matter weight, 1000-grain weight and yield. The effects of full-straw mulching were better than those of half-straw mulching. Under the same mulch rates, the effect of tillage was better than no-tillage. The organic matter, readily available K and available P in soil were increased by straw mulching, which was more evident under no-tillage condition although soil organic matter content was slightly decreased without straw mulching. The soil water content was increased by straw mulching, and the effect of full-straw mulching was better than that of half-straw mulching. These results showed that straw mulching can alleviate the harmful effect of drought to a certain extent, and at the same time can increase soil nutrient content. Moreover, the combined effect of straw mulching and no-tillage on increasing soil nutrient content was more evident.
  • Authors:
    • Moraes, A.
    • Balbinot Junior, A.
    • Backes, R.
  • Source: PLANTA DANINHA
  • Volume: 25
  • Issue: 3
  • Year: 2007
  • Summary: Straw on the soil significantly reduces weed infestation under no-tillage system. The potential of winter cover crops and their management timing in reducing weed infestation in maize crop were studied in Canoinhas, Santa Catarina, Brazil, in 2003/04 and 2004/05. In the first experiment, 6 winter cover crops were investigated: oilseed radish, black oat [ Avena nuda], rye, ryegrass [ Lolium sp.], intercropped among black oat and common vetch [ Vicia sativa] and among oilseed radish, black oat, rye, ryegrass and common vetch. These cover crops were slashed down at three different times before maize sowing (1, 10 and 25 days). In the second experiment, the potential to reduce weed infestation was investigated in the 6 cover crops previously mentioned, plus the common vetch. The straw of ryegrass and from intercropping among the 5 species used had a high capacity to suppress weed emergence and dry matter production, while oilseed radish straw showed low weed suppression potential. The winter cover crops slashed down next to maize sowing decreased the weed infestation.
  • Authors:
    • Backes, R.
    • Moraes, A.
    • Balbinot Junior, A.
    • Souza, A.
  • Source: Scientia Agraria
  • Volume: 8
  • Issue: 2
  • Year: 2007
  • Summary: A study was undertaken in Canoinhas, Santa Catarina, Brazil, during 2004/05 season to evaluate the effect of cover crop desiccation time in relation to maize sowing on the weed infestation and maize yield. Ryegrass ( Lolium multiflorum) as a single crop and in an intercropping system (rye grass+black oat ( Avena strigosa [ A. nuda])+rye+common vetch ( Vicia sativa)+oilseed radish) were desiccated 5 times at 1, 10 20 and 30 days before maize sowing. Cover crop management near maize sowing decreased the density and mass accumulation of weeds and improved the maize grain yield.
  • Authors:
    • Piza, R.
    • Camargo, R.
  • Source: Bioscience Journal
  • Volume: 23
  • Issue: 3
  • Year: 2007
  • Summary: The effect of different cover crops on maize yield was investigated in the second no-till year, in Passos, Minas Gerais, Brazil. White oats ( Avena sativa), black oats [ Avena nuda], Brachiaria decumbens [ Urochloa decumbens] and forage turnips were cultivated in the same plots as in the previous winter, and were subsequently sown with maize. The forage crops were sown in lines in May 2004 and desiccated in October 2004, after the determination of dry matter yield. Maize was sown in each plot and the soil organic matter and grain yield were determined at the end of the cropping season. The black oats yielded the greatest amount of mulch; however, this increase did not affect the soil organic matter, in relation to all other treatments, and maize yield in the no-till system.
  • Authors:
    • Libardi, P. L.
    • Fernandes, F. C. S.
    • Silva, M. M. da
  • Source: Acta Scientiarum Agronomy
  • Volume: 29
  • Issue: Suplemento Espec
  • Year: 2007
  • Summary: The present study evaluated the effect of nitrogen levels and splittings on the chemical characteristics of a soil cropped with maize in succession to black oats at the establishment of the no tillage system. The experiment was carried out in a Red-Yellow Latosol (typic Hapludox), with 14% of clay in the 0-0.20 m soil layer. The work consisted of two maize crops (2003/04 and 2004/05) and a black oats one in between, as cover crop. The experimental design was randomized blocks in an incomplete factorial scheme, with four replications. Treatments consisted of nitrogen levels (60, 120 and 180 kg ha -1) and one control without nitrogen, besides the splittings (30 or 60 kg ha -1 at sowing, the balance in cover and 60 kg ha -1 at sowing, remaining top dressed). The following soil variables were evaluated: Ca, Mg, K, organic matter, P, H+Al, Al, sum of bases, CEC, pH and base saturation V(%). Ammonium sulfate fertilization top dressed promoted a pH decrease in all treatments after the second maize crop and the increase in the level of N decreased the contents of soil Ca, Mg and K.
  • 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.
  • Authors:
    • Pereira, J.
    • Prior, M.
    • Uribe-Opazo, M.
    • Nobrega, L.
    • Lopes, R.
  • Source: Acta Scientiarum Agronomy
  • Volume: 29
  • Issue: Suplemento Espec
  • Year: 2007
  • Summary: This study evaluated alterations in the physical properties water content, soil density and porosity in areas under no tillage and tillage systems in the cultures of soybean and maize in three agricultural years. The experiment was carried out at the Experimental Nucleus of Agricultural Engineering of Unioeste (Cascavel, state of Parana). Soybean culture occurred in the first two years and in the third year maize, as summer crop, black oats and forage turnip as winter cover crops. During these three years the study observed reduction of water content and soil density and increase of porosity. The variations as regards the physical properties of the soil showed direct proportional relation between water content and soil density and was in inverse proportion for soil porosity. The soil presented improvements on its physical conditions for the porosity increase and density reduction with the black oats and forage turnip crops and maize. The soybean/maize management in rotation with black oats and forage turnip showed more adequate in the improvement of the physical conditions of the soil as compared with the management systems, since neither of the systems had a major impact in the improvements of the physical properties evaluated throughout this whole period.