• Authors:
    • Singh, A.
    • Kumar, R.
    • Pathak, H.
    • Jain, N.
    • Sasmal, S.
    • Bhatia, A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 136
  • Issue: 3
  • Year: 2010
  • Summary: No-till farming in wheat is being practiced in the rice-wheat system of the Indo-Gangetic plains of south Asia for resource conservation. No-tillage leads to mitigation of carbon dioxide emission, but may emit more nitrous oxide (N2O) as compared to conventional tillage reducing mitigation benefit. The aim of this study was assessment of N2O emission in wheat grown under conventional and no-tillage and its mitigation using two new nitrification inhibitors, viz. S-benzylisothiouronium butanoate (SBT-butanoate) and S-benzylisothiouronium furoate (SBT-furoate). Cumulative emission of N2O-N was higher under no-tillage by 12.2% with urea fertilization and from 4.1 to 4.8% for the inhibitor treatments as compared to the conventional tillage. In no-tillage total emission of N2O-N reduced from 0.43% of applied N with urea to 0.29% of applied N with SBT-furoate treatment. The N2O-N emissions in SBT-butanoate treatment were at par with the standard dicyandiamide (DCD) inhibitor treatment. Water-filled pore space (WFPS) was higher on most days under no-tillage, with the largest emissions (>1000 mu g N2O-N m(-2) day(-1)) coming with nitrification of ammonium-N present in soil below 60% WFPS. Carbon efficiency ratio was highest (48.1) from SBT-furoate treatment under conventional tillage. The nitrification inhibitors used in the study increased yield of wheat, reduced global warming potential by 8.9-19.5% over urea treatment and may be used to mitigate N2O emission.
  • Authors:
    • Wruck, F.
    • Feigl, B.
    • Bernoux, M.
    • Cerri, C.
    • Raucci, G.
    • Carvalho, J.
    • Cerri, C.
  • Source: Soil & Tillage Research
  • Volume: 110
  • Issue: 1
  • Year: 2010
  • Summary: Changes in land use can result in either sources or sinks of atmospheric carbon (C), depending on management practices. In Brazil, significant changes in land use result from the conversion of native vegetation to pasture and agriculture, conversion of pasture to agriculture and, more recently, the conversion of pasture and agriculture to integrated crop-livestock systems (ICL). The ICL system proposes a diversity of activities that include the strategic incorporation of pastures to agriculture so as to benefit both. In agricultural areas, for example, the implementation of ICL requires the production of quality forage for animals between crops as well as the production of straw to facilitate the sustainability of the no-tillage (NT) management system. The objective of this study was to evaluate the modifications in soil C stocks resulting from the main processes involved in the changes of land use in Amazonia and Cerrado biomes. For comparison purposes, areas under native vegetation, pastures, crop succession and ICL under different edapho-climatic conditions in Amazonia and Cerrado biomes were evaluated. This study demonstrated that the conversion of native vegetation to pasture can cause the soil to function either as a source or a sink of atmospheric CO 2, depending on the land management applied. Non-degraded pasture under fertile soil showed a mean accumulation rate of 0.46 g ha -1 year -1. Carbon losses from pastures implemented in naturally low fertile soil ranged from 0.15 to 1.53 Mg ha -1 year -1, respectively, for non-degraded and degraded pasture. The conversion of native vegetation to agriculture in areas under the ICL system, even when cultivated under NT, resulted in C losses of 1.31 in six years and of 0.69 Mg ha -1 in 21 years. The conversion of a non-degraded pasture to cropland (soybean/sorghum) released, in average, 1.44 Mg of C ha -1 year -1to the atmosphere. The ICL system in agricultural areas has shown evidences that it always functions as a sink of C with accumulation rates ranging from 0.82 to 2.58 Mg ha -1 year -1. The ICL produces soil C accumulation and, as a consequence, reduces atmospheric CO 2 in areas formerly cultivated under crop succession. However, the magnitude of C accumulation in soil depends on factors such as the types of crops, the edapho-climatic conditions and the amount of time the area is under ICL.
  • Authors:
    • Delve, R. J.
    • Zingore, S.
    • Nyawasha, R. W.
    • Nyamangara, J.
    • Masvaya, E. N.
    • Giller, K. E.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 88
  • Issue: 1
  • Year: 2010
  • Summary: This paper examines a number of agronomic field experiments in different regions of sub-Saharan Africa to assess the associated variability in the efficiencies with which applied and available nutrients are taken up by crops under a wide range of management and environmental conditions. We consider N and P capture efficiencies (NCE and PCE, kg uptake kg(-1) nutrient availability), and N and P recovery efficiencies (NRE and PRE, kg uptake kg(-1) nutrient added). The analyzed cropping systems employed different soil fertility management practices that included (1) N and P mineral fertilizers (as sole or their combinations) (2) cattle manure composted then applied or applied directly to fields through animal corralling, and legume based systems separated into (3) improved fallows/cover crops-cereal sequences, and (4) grain legume-cereal rotations. Crop responses to added nutrients varied widely, which is a logical consequence of the wide diversity in the balance of production resources across regions from arid through wet tropics, coupled with an equally large array of management practices and inter-season variability. The NCE ranged from 0.05 to 0.98 kg kg(-1) for the different systems (NP fertilizers, 0.16-0.98; fallow/cover crops, 0.05-0.75; animal manure, 0.10-0.74 kg kg(-1)), while PCE ranged from 0.09 to 0.71 kg kg(-1), depending on soil conditions. The respective NREs averaged 0.38, 0.23 and 0.25 kg kg(-1). Cases were found where NREs were > 1 for mineral fertilizers or negative when poor quality manure immobilized soil N, while response to P was in many cases poor due to P fixation by soils. Other than good agronomy, it was apparent that flexible systems of fertilization that vary N input according to the current seasonal rainfall pattern offer opportunities for high resource capture and recovery efficiencies in semi-arid areas. We suggest the use of cropping systems modeling approaches to hasten the understanding of Africa's complex cropping systems.
  • Authors:
    • Onwugbuta-Enyi, J.
    • Offor, U. S.
  • Source: Journal of Agriculture and Social Research (JASR)
  • Volume: 10
  • Issue: 1
  • Year: 2010
  • Summary: The work was carried out to study the effects of Palm Bunch Ash (PBA) on seed germination, seedling growth and biochemical parameters of Soybean. Soybean seeds were raised in petri-dishes and irrigated with different concentrations of PBA (0-control, 10, 25,40,65,80 and 100%). At lower concentrations, PBA had promotory effects on all the parameters studied while 100% concentration had inhibitory effects.
  • Authors:
    • Brandenburg, R. L.
    • Pembroke, B.
    • Gowen, S. R.
    • Osei, K.
    • Jordan, D. L.
  • Source: Journal of Nematology
  • Volume: 42
  • Issue: 3
  • Year: 2010
  • Summary: Root-knot nematode is an important pest in agricultural production worldwide. Crop rotation is the only management strategy in some production systems, especially for resource poor farmers in developing countries. A series of experiments was conducted in the laboratory with several leguminous cover crops to investigate their potential for managing a mixture of root-knot nematodes (Meloidogyne arenaria M. incognita, M. javanica). The root-knot nematode mixture failed to multiply on Mucuna pruriens and Crotalaria spectabilis but on Dolichos lablab the population increased more than 2-fold when inoculated with 500 and 1,000 nematodes per plant. There was no root-galling on M. pruriens and C. spectabilis but the gall rating was noted on D. lablab. Greater mortality of juvenile root-knot nematodes occurred when exposed to eluants of roots and leaves of leguminous crops than those of tomato; 48.7% of juveniles died after 72 It exposure to root eluant of C. spectabilis. The leaf eluant of D. lablab was toxic to nematodes but the root eluant was not. Thus, different parts of a botanical contain different active ingredients or different concentrations of the same active ingredient. The numbers of root-knot nematode eggs that hatched in root exudates of M. pruriens and C. spectabilis were significantly lower (20% and 26%) than in distilled water, tomato and P vulgaris root exudates (83%, 72% and 89%) respectively. Tomato lacks nematotoxic compounds found in M. pruriens and C. spectabilis. Three months after inoculating plants with 1,000 root-knot nematode juveniles the populations in pots with M. prurient, C. spectabilis and C. retusa had been reduced by approximately 79%, 85% and 86% respectively; compared with an increase of 262% nematodes in pots with Phaseolus vulgaris. There was significant reduction of 90% nematodes in fallow pots with no growing plant. The results from this study demonstrate that some leguminous species contain compounds that either kill root-knot nematodes or interfere with hatching and affect their capacity to invade and develop within their roots. M. pruriens, C. spectabilis and C. retusa could be used with effect to decrease a mixed field populations of root-knot nematodes.
  • Authors:
    • Dagar, J. C.
    • Chaudhari, S. K.
    • Pandey, C. B.
    • Singh, G. B.
    • Singh, R. K.
  • Source: Soil & Tillage Research
  • Volume: 110
  • Issue: 1
  • Year: 2010
  • Summary: Tillage is known to reduce soil organic carbon (SOC) and increase soil N mineralization, but information on the level of tillage that increases net soil N mineralization and simultaneously maintains a considerable amount of SOC is poorly known. This study investigated the effect of four levels of tillage (15-cm deep by a local made plough) on net soil N mineralization rate (NMR), net nitrification rate (NNR), pools of NO(3)(-)-N and NH(4)(+)-N, and microbial biomass carbon (MB-C), water content of soil (WCS) and soil temperature (ST) in a Dystric fluvisols in the hot humid tropical climate of South Andaman Island of India. We hypothesized that: (1) tillage would increase NMR and reduce amount of SOC. But, these changes would depend on frequency of the tillage, i.e. greater would be the tillage frequency; higher, the NMR and decline in the amount of SOC; (2) low tillage would increase NMR, but reduce SOC nearly equal to short term zero tillage. Tillage levels included: (1) long term zero till (not tilled from 1983 to 2002; then from 2003 to 2006 crops (maize-okra rotation) were sown by dibbling, and weeds were cut and mulched), (2) frequent till (tilled three times before each crop sowing in the crop rotation from 1983 to 2002 and 2003 to 2006 as well; weeds were removed), (3)low till (not tilled from 1983 to 1999; then tilled once before each crop sowing in the crop rotation from 2000 to 2002 and weeds were removed; from 2003 to 2006 tilled like 2000-2002, but weeds were uprooted and buried in situ), and (4) short term zero till (from 1983 to 2002 tillage history was the same as in the low till; from 2003 to 2006 the crops were sown by dibbling in the crop rotation and weeds were cut and mulched in situ). Maize (Zea mays L.) was cultivated during wet season (WS, May to October) and okra (Abelmoschus esculentus L) during post-wet season (PWS, November to January) in all tillage treatments. Soils were sampled in all tillage treatments (levels) across the WS, PWS and dry (DS, February to April) seasons over two annual cycles (2004-2005 and 2005-2006) and analyses were done for the parameters investigated. We found that WCS was the highest (44-48%) during the WS and the lowest (10-16%) during the DS, however, ST was the lowest (25.5-26.5 degrees C) during the WS and the highest (30.5-33.4 degrees C) during the DS in all tillage treatments. Across the tillage levels, NMR increased from 1.06 to 1.96 mu g g(-1), day(-1) and NNR from 1.21 to 1.88 mu g g(-1) day(-1), and pools of NO(3)(-)-N and NH(4)(-)-N from 3.98 to 11.1 mu g g(-1) and 24.76 to 42.51 mu g g(-1), respectively. The increase was, however, the highest in the frequent till and the lowest in the long term zero till treatment. The NMR and NNR were the lowest (0.53-0.93.1 mu g g(-1), day(-1) and 0.49-0.86 mu g g(-1) day(-1), respectively) during the WS and the highest (1.09-1.71 mu g g(-1) day(-1) and 1.06-1.61 mu g g(-1) day(-1)) during the PWS in all tillage treatments. The NMR was positively correlated with the MB-C in all tillage treatments. Concurrent with the increase in the NMR, the SOC declined in all tillage treatments, but the decline was the highest in the frequent till and the lowest in the long term zero till treatment. Across the tillage treatments, the MB-C was correlated to the SOC. The SOC in the low till (7. 9 mg g(-1)) treatment was nearly equal to that in theshort term zero till treatment (8.8 mg g(-1)), but NMR was higher (0.86 mu g g(-1) day(-1)) particularly during the WS when plant's demand for N is usually high. Our results supported both the hypotheses, and suggested that low tillage might be a good option for soil fertility maintenance and carbon stock build-up in the soils of the hot humid tropics. (C) 2010 Elsevier B.V. All rights reserved.
  • Authors:
    • Dalal, R. C.
    • Blamey, F. P. C.
    • Rao, A. S.
    • Rao, D. L. N.
    • Mohanty, M.
    • Reddy, K. S.
    • Dixit, S. K.
    • Pandey, M.
    • Menzies, N. W.
  • Source: Proceedings of the 19th World Congress of Soil Science, Soil Solutions for a Changing World, 1–6 August 2010, Brisbane, Australia
  • Year: 2010
  • Summary: The Mother Baby Trial (MBT) approach is an on-farm participatory mechanism to introduce and test technology options suited to a heterogeneous community. In this study, the MBT concept was followed with integrated nutrient management (INM) technology in a soybean-wheat system. Seven treatments were tested in Mother trials in 2005-06 and 2006-07 on farmers' fields in the Rajgarh and Bhopal districts of Central India. In 2007-08, 100 Baby trials were conducted by farmers in 10 surrounding villages to demonstrate and test the INM technology. The Baby trials were based on the results of Mother trials which showed that INM using 50% of the recommended NPKS fertilizer+5 t FYM/ha+ Rhizobium to soybean and 75% of the recommended NPKS fertilizer+P-solubilizing bacteria to wheat produced higher soybean yield by 46% and higher wheat yield by 24% over the farmers' practice. In the Baby trials, there was a wide variation in soybean yield obtained with INM, balanced fertilization (BF) using inorganic fertilizers, and farmers' practice; in poorer yielding trials, some problems were evident in the control of weeds and insect pests. Wheat responded well to BF and INM in trials irrigated 3-4 times. The MBT approach proved valuable in demonstrating higher productivity of the soybean-wheat system, and the value of INM and BF technologies, but only with proper weed and pest management in soybean, and adequate irrigation in wheat, as a package of practices.
  • Authors:
    • Sa, M. E. de
    • Lazarini, E.
    • Silva, J. B. da
    • Vieira, R. D.
  • Source: Revista Brasileira de Sementes
  • Volume: 32
  • Issue: 2
  • Year: 2010
  • Summary: During the maturation and harvest of soybean (Glycine max (L.) Merr.) seed the ideal climatic conditions include dryness and lower temperatures. Using winter-sown (July to September) soybean we verified the effects of irrigation on the physiological quality of soybean seeds during maturity using a factorial treatment design with three varieties (IAC-19, Conquista and IAC 8-2) and two irrigation interruption times (starting at stage R 7 and irrigating until 14 days after stage R 8). The samples were taken at stage R 7 and at 3 days, 7 days, 10 days, 14 days (stage R 8) and 28 days after starting stage R 7. We evaluated the percentage germination, vigor using accelerated aging and electric conductivity tests, and the percentage of spotted and imperfect seeds and found that irrigation after stage R 7 does not reduce seed quality but can improve the physiological potential of the seeds.
  • Authors:
    • Indrakumar, N.
    • Jayapalaiah, G. P.
    • Sreenatha, A.
  • Source: International Journal of Agricultural Engineering
  • Volume: 3
  • Issue: 2
  • Year: 2010
  • Summary: Finger millet also known as Ragi or Mandwa is the most important small millet food and fodder crop. It is extensively cultivated in Asian countries like India, Ceylon, Malaysia, China, Nepal and Japan and African countries. It is widely grown in Karnataka, Tamil Nadu, Andhra Pradesh, Orissa, Bihar, Gujarat and Maharashtra and in the hilly regions of Uttar Pradesh, Sikkim and Himachal Pradesh. Karnataka is a major finger millet producing state in India covering about 43 per cent area of finger millet cultivation and producing nearly 49 per cent of the total food grain production (Anonymous, 2010). This crop is grown both in dryland as well as in irrigated conditions where irrigation facilities are available and it constitute only 5 per cent area of the finger millet grown in Karnataka. Whereas the rain fed finger millet is about 95 per cent and usually it is grown in Kharif and irrigated finger millet in Rabi or summer. Finger millet is often intercropped with legumes if it is grown under rain fed condition. Finger millet has outstanding properties as a subsistence food crop. Its small seeds can be stored safely for many years without insect damage, which makes it a traditional component of farmers' risk avoidance strategies in drought-prone regions of Eastern Africa and South Asia. Because the seed can be stored for decades (some say 50 years), it is highly valued as a reserve against famines. Finger millet is especially valuable as it contains the amino acid methionine, which is lacking in the diets of hundreds of millions of the poor who live on starchy staples such as cassava, plantain, polished rice, or maize meal. Finger millet can be ground and cooked into cakes, puddings or porridge. The grain is made into a fermented drink (or beer) in Nepal and in many parts of Africa. The straw from finger millet is used as animal fodder.
  • Authors:
    • Sujatha, S.
    • Bhat, R.
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 7
  • Year: 2010
  • Summary: A 5-year field trial to assess the impact of microsprinkler irrigation and nutrition on vanilla grown as intercrop in arecanut plantation was conducted on a laterite soil. Pooled analysis indicated that microsprinkler irrigation at 1.0 Epan resulted in significantly higher green bean yield (842 kg ha -1) than 0.75 Epan (579 kg ha -1). Organic manure application in the form of vermicompost (720 kg ha -1) and FYM (768 kg ha -1) and recommended NPK (718 kg ha -1) produced green bean yield at par with recycling of gliricidia prunings (625 kg ha -1). Irrigation at 1.0 Epan proved superior by registering maximum benefit:cost (B:C) ratio of 2.25 compared to 1.62 at 0.75 Epan. The highest B:C ratio was obtained with recommended NPK (2.27) followed by recycling of gliricidia prunings (2.10), vermicompost (1.87), vermicompost+arecanut husk mulching (1.80) and FYM (1.64). The soil pH increased by 0.4 units in 2008 compared with the pre-experimental soil pH of 5.6 in 2004. Nutrition alone and in combination with irrigation had significant impact on soil pH. Organic manure application increased the soil pH (6.1-6.2) significantly over recommended NPK (5.6) at the end of experiment in 2008. Significant variation in soil organic carbon (SOC) was noticed due to different nutrition treatments. Application of vermicompost and FYM significantly increased the SOC content by 38-54% in 2008 over initial levels in 2004. Bray's P availability was influenced by nutrition and its interaction with irrigation. Application of FYM continuously for 4 years has resulted in significant increase in Bray's P content (41.3 mg kg -1) compared to other nutrition treatments (9.4-17.2 mg kg -1). Irrigation equivalent to 0.75 Epan (223 mg kg -1) increased the K availability significantly over 1.0 Epan (172 mg kg -1). The K availability was significantly higher in recommended NPK (416 mg kg -1) than in other organic treatments (98-223 mg kg -1) at 0-30 cm soil depth. Overall, vanilla responded well to irrigation and nutrition in arecanut-based cropping system with a better economic output and improved soil fertility.