• Authors:
    • Joergensen, R.
    • Formowitz, B.
    • Buerkert, A.
  • Source: Plant and Soil
  • Volume: 325
  • Issue: 1/2
  • Year: 2009
  • Summary: Many microbial turnover processes in acidic sandy subtropical soils are still poorly understood. In a 59-day pot and a 189-day laboratory incubation experiment with two West African continuous cereal soils, the effects of 2 mg g -1 root residues were investigated on growth of sorghum seedlings, soil microbial biomass and activity indices, using cowpea, groundnut, pearl millet, maize and sorghum. The effects of root residues were compared with mineral P or mineral P+N treatments and with a non-fertilized control treatment. On the Alfisol (Fada, Burkina Faso), shoot dry mass was always significantly higher than on the Ultisol (Koukombo, Togo). Highest shoot dry mass was observed after application of mineral P+N on the Alfisol and after mineral P alone on the Ultisol. The application of legume root residues led to small and non-significant increases in dry mass production compared to the non-amended control, whereas the application of cereal root residues led to a decline, regardless of their origin (millet, maize or sorghum). Contents of microbial biomass C, microbial biomass N and ergosterol were 75 to 100% higher in the Alfisol than in the Ultisol, while ATP was only 36% higher. Organic amendments increased ergosterol concentrations by up to 145% compared to the control and mineral P application. Microbial biomass C and microbial biomass N increased by up to 50% after application of root residues, but ATP only up to 20%. After application of legume root residues, cumulative CO 2 production was similar in both soils with an average of 370 g CO 2-C g -1 over 189 days. After application of cereal root residues, cumulative CO 2 production was higher in the Alfisol (530 g g -1) than in the Ultisol (445 g g) over 189 days.
  • Authors:
    • Gentry, T.
    • Aitkenhead-Peterson, J.
    • Gonzalez-Chavez, M.
    • Zuberer, D.
    • Hons, F.
    • Loeppert, R.
  • Source: Soil & Tillage Research
  • Volume: 106
  • Issue: 2
  • Year: 2009
  • Summary: Tillage and crop rotation/intensity can influence soil biological properties and relevant soil processes including C sequestration. This study determined the effects of long-term (25 years) no till (NT) and conventional tillage (CT) management and cropping sequence [continuous wheat (CW; Triticum aestivum L.) and a rotation of sorghum ( Sorghum bicolor L. Moench), wheat and soybean (RW; Glycine max L. Merr)] on soil microbial community structure and labile and recalcitrant microbial bio-products in central Texas. Fatty acid methyl ester (FAME) profiles, microbial biomass (MB-C, -N and -P), hot water extractable soil carbohydrates (HWE-SC) and easily extracted- (EE-) and total-glomalin-related soil proteins (T-GRSP) were analyzed. Principal component analysis of the FAME data indicated that crop management modified and selected microbial populations. In general, NT-RW resulted in the greatest richness and biodiversity of the total microbial community, soil organic C, MB-P, HWE-SC, EE- and T-GRSP. No tillage increased labile and more recalcitrant bio-products, soil organic C and total N compared to CT. The soil microbial biomass C:N:P ratio, an indicator of ecosystem nutrient limitation, suggested that the CT-RW treatment may have a soil P limitation, which was not observed in the other treatments. The treatments preferentially selected for different microbial communities, which generated microbial products that significantly influenced soil C and N retention. Our results suggested that NT in conjunction with crop rotation (RW) can be recommended for increased soil C sequestration.
  • 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:
    • Garcia, R.
    • Dornelles, M.
    • Lima, A.
    • Coelho, F.
    • Lima, E.
  • Source: Revista Ceres
  • Volume: 56
  • Issue: 6
  • Year: 2009
  • Summary: The objective of this work was to evaluate a number of soybean agronomic characteristics in green manuring succession with two types of residue management. An experiment arranged in a complete randomized block design with four repetitions distributed in a split-plot scheme was carried out in Campos dos Goytacazes-RJ, in the agricultural year 2001/2002. The plots consisted of two managements (with and without clipping) and the subplots consisted of the cover species (black oat, millet, forage sorghum, teosinte, forage radish, dwarf velvet bean, white lupin, pigeonpea, and spontaneous vegetation). In the treatment without clipping, the mean grain yield of soybean in succession with black oat and spontaneous vegetation was 50% higher than the succession with dwarf velvet bean, millet, pigeonpea and forage sorghum. However, in the treatment with clipping, the mean grain yield in succession with millet, teosinte and spontaneous vegetation was 79% higher than the succession with lupin and dwarf velvet bean. The management of millet with mechanical clipping resulted in the increase of 1.154 kg ha -1 of soybean compared wih the treatment without management.
  • Authors:
    • Cargnelutti Filho, A.
    • Assis, R.
    • Procopio, S.
    • Monteiro, F.
    • Pires, F.
    • Pacheco, L.
    • Carmo, M.
    • Petter, F.
  • Source: Planta Daninha
  • Volume: 27
  • Issue: 3
  • Year: 2009
  • Summary: The objective of this experiment was to evaluate the efficiency of soybean oversowing, using cover crops, in reducing weed emergence and its reflections on the productivity of the soybean cultivated in the following season. The experiment was arranged in a randomized block design, in split-plot, with four replications. The soybean was sown four times: (1) 10/27/2005, (2) 11/10/2005, (3) 11/24/2005 and (4) 12/14/2005, under a no-tillage system, corresponding to four times of soybean oversowing, occurring respectively, on 01/30/2006; (b) 02/13/2006; (c) 02/22/2006; and (d) 03/14/2006. Six cover crops were evaluated [ Brachiaria brizantha, B. ruziziensis, B. decumbes, Eleusine coracana, Pennisetum glaucum and cover crop-sorghum hybrid ( Sorghum bicolor cv. Bicolor) with Sudan-grass ( Sorghum bicolor cv. Sudanense)] and untreated (spontaneous vegetation) in four oversowing times. Oversowing was performed manually when the soybean reached the R 7 stadium (beginning of defoliation during physiological maturation), in each of the four sowing times of the 2005/06 soybean crop. The first cover crop desiccation was carried oat on 10/23/2006. After 20 days, the second desiccation was applied, followed by soybean sowing, cultivar MSOY 6101, early cycle, 0.45 m spaced, aimed at a population of 500.000 plants ha -1. Soybean oversowing, especially when using brachiaria, showed to be an important tool for the integrated management of weed plants, since it provides a larger biomass contribution and soil cover and sustainability to no-till systems in the cerrado.
  • Authors:
    • Oliveira, E.
    • Baliza, D.
    • Rodrigues, T.
    • Avila, F.
    • Faquin, V.
    • Rodrigues, C.
  • Source: CIENCIA E AGROTECNOLOGIA
  • Volume: 33
  • Issue: 6
  • Year: 2009
  • Summary: This study investigated the effect of the previous cultivation of different forage grasses fertilized with triple superphosphate (TSP) and reactive Arad phosphate (RAP) on growth, yield, and accumulation of P by soyabean. Two experiments were carried out: one in Haplic Cambisol typical distrophic, medium texture and the other in Red Latosol typical distrophic very clayey texture. For both experiments, the experimental design was a completely randomized one in a 4*2*2 factorial scheme; the previous crop being of four forage grasses utilized as cover plants in no-tillage system ( Brachiaria decumbens [Urochloa decumbens], Brachiaria brizantha [U. brizantha], millet and forage sorghum) fertilized with two sources of P (RAP and TSP) and two additional treatments, which are the cultivation of soyabean and bean plant without the previous growing of cover plants, and also fertilized with TSP and RAP. The plants were harvested after they had completed the development cycle. Grain and shoot dry matter yield and P accumulation in the shoot and in the grains of soyabean were determined. The forage plants immobilized the P of TSP, reducing the residual effect for soyabean. When forage grasses are fertilized with RAP, there is increased residual effect with increasing yield of soyabean in succession to the cover plants, with exception for the growing in succession to B. brizantha.
  • Authors:
    • White, P. M.
    • Rice, C. W.
  • Source: Soil Science Society of America Journal
  • Volume: 73
  • Issue: 1
  • Year: 2009
  • Summary: One goal of soil C sequestration is to increase the mass of C stored in agricultural soils. Reducing soil disturbance, e.g., no-till management, facilitates soil fungal growth and results in higher C sequestration rates; however, the specific mechanisms associated with short-term plant residue C and N retention are less clear. We applied 13C- and 15N-enriched grain sorghum ( Sorghum bicolor) residue to no-till (NT) and conventional tillage (CT) soils, and measured the 13C and 15N retention in the soil and in aggregate fractions, along with soil microbial dynamics, during a growing season. The field site was located at Ashland Bottoms near Manhattan, Kansas. The added plant residue mineralized rapidly in both tillage systems, with similar decomposition kinetics, as indicated by 13C data. Mass balance calculations indicated that approximately 70% of the added 13C was mineralized to CO 2 by 40 days. The total Gram positive and Gram negative bacteria and fungal phospholipid fatty acids were higher under NT 0-5 cm during the most active period of residue mineralization compared with the CT 0-5 or 5-15 cm depths. No changes were observed in the NT 5-15 cm depth. The >1000-m aggregate size class retained the most 13C, regardless of tillage. The NT >1000-m aggregates retained more 15N at the end of the experiment than other NT and CT aggregates size classes. Data obtained indicate higher biological activity associated with NT soils than under CT, and increased retention of plant residue C and N in macroaggregates.
  • 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:
    • Jorge, R. F.
    • Cora, J. E.
    • Martins, M. dos R.
    • Marcelo, A. V.
  • Source: Soil & Tillage Research
  • Volume: 104
  • Issue: 1
  • Year: 2009
  • Summary: The adaptation of no-tillage system in tropical regions depends on the suitable choice of summer and winter crops which should contribute to improvement of soil properties. The aim of the present study was to determine the effect of crop sequences on soil aggregation and contents of organic C and polysaccharides in aggregates of a Rhodic Eutrudox under no-tillage. The treatments consisted of the combination of four summer crop sequences and seven winter crop sequences. The summer crop sequences were: maize monocrop ( Zea mays L.) (MM); soybean monocrop ( Glycine max (L.) Merrill) (SS); crop sequence of soybean/maize/soybean/maize (SM); crop sequence of rice ( Oryza sativa L.)/bean ( Phaseolus vulgaris L.)/cotton ( Gossypium hirsutum L.)/bean (RB). The winter crops were: maize, sunflower ( Helianthus annuus L.), radish ( Raphanus sativus L.), pearl millet ( Pennisetum americanum (L.) Leeke), pigeon pea ( Cajanus cajan (L.) Millsp), grain sorghum ( Sorghum bicolor (L.) Moench) and sunn hemp ( Crotalaria juncea L.). The highest total organic C, total polysaccharides and dilute acid-extracted polysaccharides contents were found in 2.00-1.00 mm water-stable aggregates and the lowest contents were found in