• Authors:
    • Di Tizio, A.
    • Campiglia, E.
    • Mancinelli, R.
    • Marinari, S.
  • Source: Applied Soil Ecology Volume 46, Issue 1, September 2010, Pages
  • Volume: 46
  • Issue: 1
  • Year: 2010
  • Summary: Carbon sequestration in soil is an important means for reducing net emissions of CO(2) into the atmosphere. We hypothesized that organic cropping systems (ORG) would reduce soil CO(2) emission and increase C storage compared to conventional cropping systems (CONV). The objectives of this study were to: (i) analyze the ORG and CONV systems in terms of soil CO(2) emission and soil C balance and (ii) establish if the soil in the ORG and CONV systems represents a source or a sink of C. A3-year crop rotation (durum wheat-Triticum durum Desf., tomato - Licopersicum esculentum Mill., and pea - Pisum sativum L) was carried out in both cropping systems, but the crop rotation was implemented with common vetch (Vicia sativa L.) before tomato planting and sorghum (Sorghum bicolor (L) Moench.) before pea sowing and both green manured only in the ORG system. It was found that the soil CO(2) emission rate at peak times (in spring or at the end of summer - beginning of autumn) in the ORG system was higher than the CONV system. The peak of CO(2) was attributed to the fact that at this time the soil temperature and the relative soil water content (RWC) were probably in the optimal range for soil respiration (17.2 degrees C and 36.4% of RWC) and the difference between ORG and CONV was probably due to the green manuring of the cover crops in the ORG system. However, even if the cropping systems had a temporary impact on the rate of soil CO(2) emissions, the soil C output calculated as the average of cumulative CO(2) emission over the 3-year period did not show significant differences between the ORG and CONV systems (8.98 Mg C-CO(2) ha(-1) vs. 8.06 Mg C-CO(2) ha(-1)). On the other hand, the C input in the ORG system was higher than in the CONV (9.46 Mg C ha(-1) vs. 5.57 Mg C ha(-1)) as well as the C input/output ratio (1.10 vs. 0.72). The 3-year average of TOC content and C stock were higher in the ORG than in the CONV system (1.24% vs. 1.10% and 27.4 Mg C ha(-1) vs. 23.9 Mg C ha(-1), respectively). However, the decrease of TOC and C stock over 3 years period suggested that further studies over a longer period are needed to verify if C limitation for soil microbial growth and nitrogen limitation for crop growth in the organic system could hinder soil C accumulation over a longer period. (C) 2010 Elsevier B.V. All rights reserved.
  • Authors:
    • Moscatelli, M. C.
    • Lagomarsino, A.
    • Marinari, S.
    • Di Tizio, A.
    • Campiglia, E.
  • Source: Soil & Tillage Research
  • Volume: 109
  • Issue: 2
  • Year: 2010
  • Summary: The scientific literature regarding the use of C and N mineralization kinetics as a tool to highlight the effects of different cropping systems on soil C and N release is scarce. In this study we aimed to assess the effectiveness of these parameters in evaluating soil C and N potential release in organic (ORG) and conventional (CONV) three-year cropping systems. A long-term field study was established in 2001 at the University of Tuscia experimental farm (Viterbo, Italy) in a randomized block design. The soil is classified as Typic Xerofluvent or Dystric Fluvisol. In the CONV system the Good Agricultural Practice is adopted, whereas the ORG system is managed following the Regulation 2092/91/EEC. Both systems had a three-year crop rotation (pea - Pisum sativum L.; durum wheat - Triticum durum Desf.; tomato - Licopersicum esculentum Mill.). One of the main differences between the two systems is the soil N fertilization program: organic fertilizers (Guano: 6% N, 32% organic carbon and DIX10: 10% N, 42% organic carbon, both produced by Italpollina. Italy) and mineral nitrogen fertilizers (NH(4)NO(3)) were applied to ORG and CONV fields.respectively. Moreover, the rotation in the ORG system included common vetch (Vicia sativa L) and sorghum (Sorghum vulgare L) as green manure crops. Our results supported the hypotheses in that the two systems differed significantly on potentially mineralizable C (C(o)) in 2008 and on potentially mineralizable N (N(o)) as nitrate form (N(0)-NO(3)(-)) in 2006 (318 mu g C-CO(2) g(-1) 28 d(-1) vs. 220 mu g C-CO(2) g(-1) 28 d(-1); 200 mu g N-NO(3)(-) g(-1) vs. 149 mu g N-NO(3)- g(-1) in ORG and CONV, respectively). The reduction of N(o) in soil during the crop rotation period could reflect the N microbial immobilization since a negative correlation between microbial biomass N:total N ratio and No as ammonium form (N(0)-NH(4)(+))(P < 0.001) as well as a positive correlation between N0-NH4+ and C:N ratio of microbial biomass (P < 0.05) were observed. Moreover, a lower potential mineralization rate of N was observed in soil with Guano (25%) than in soil with DIX10 (35%); nevertheless the former fertilizer might cover a longer period of crop N demand as a more gradual release of N0 was observed. In this work we demonstrated that the use of mineralization kinetics parameters can offer a potential to assess the mineralization–immobilization processes in soils under different climatic and management conditions. Moreover, they can be used to evaluate the most suitable N release pattern of organic fertilizers used in various cropping systems.
  • 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:
    • Meijide, A.
    • Sanz-Cobena, A.
    • Sanchez-Martin, L.
    • Quemada, M.
    • Vallejo, A.
  • Source: European Journal of Soil Science
  • Volume: 61
  • Issue: 5
  • Year: 2010
  • Summary: The aim of this study was to evaluate the pattern of nitrous oxide (N 2O) and methane (CH 4) fluxes, and leaching losses of nitrate (NO 3-) and dissolved organic C (DOC), during a fallow-onion crop-fallow cycle in a Mediterranean area. The importance of the fallow (intercrop) period and the type of fertilizer were also evaluated. Goat and chicken manure (M) from an organic farm, digested pig slurry (DPS) and urea (U) were applied at a rate of 110 kg N ha -1 and compared with a zero N treatment (Control). The crop period contributed more than each fallow period to the total N 2O emission (ranging from 70 to 85% of the total emission, depending on the treatment). The variability of rainfall during fallow periods affected N 2O emissions, with the highest fluxes observed in the second fallow, which was the wetter. Negative net fluxes of N 2O (0 to -0.4 mg N 2O-N m -2 day -1) were mainly observed during the irrigation period and in fallow periods. The type of fertilizer had no effect on N 2O fluxes, but influenced the CH 4 oxidation. The largest CH 4 emission was from the manure treatment (2.4 mg CH 4-C m -2 day -1) during the irrigation period. The lowest NO 3- but highest DOC leaching rates were measured during the second fallow period from the manure treated plots (0.2 kg NO 3--N ha -1 and 3.9 kg C ha -1), which also had the highest drainage. The use of OM, therefore, seems to be a suitable method to reduce the environmental impacts associated with N leaching as well as increase the potential to denitrify NO 3- in groundwater.
  • Authors:
    • Pires, C. S. S.
    • Medeiros, M. A. de
    • Gravina, C. S.
    • Langer, L. F.
    • Cavalcante, K. R.
    • Togni, P. H. B.
    • Fontes, E. M. G.
    • Sujii, E. R.
  • Source: Arquivos do Instituto Biologico Sao Paulo
  • Volume: 77
  • Issue: 4
  • Year: 2010
  • Summary: The adoption of cultural practices such as companion plants and the kind of irrigation system can benefit the community of natural enemies in the agroecosystem due to the increase of more favorable microhabitats available and as a source of alternative resources, mainly in periods of low precipitation. This study evaluated how the tomato+coriander intercrop and the kind of irrigation (drip and sprinkler) could benefit the community of natural enemies in the tomato agroecosystem. This work was carried out in the experimental field of Embrapa Hortalicas, Gama, DF, from September to November 2008. The tomatoes were planted in monoculture or with coriander (companion plant) and irrigated by drip and sprinkler irrigation (three replicates per treatment), forming two groups of experimental plots according to the kind of irrigation. The community of natural enemies was sampled by the direct observation of specimens on 20 tomatoes plants per plot and in the treatments. Coriander plants were shaken over a plastic tray for collection of insects. The abundance, richness and diversity of natural enemies were higher in tomato+coriander plots, regardless of the irrigation system. We observed more species of natural enemies in tomato monoculture plots when it was irrigated by sprinkler irrigation. However, the cultural practices adopted had a different effect on each species or group of species. Therefore, in periods of low precipitation, the tomato+coriander consortium associated with sprinkler irrigation can enhance the conservation of natural enemies in the organic tomato agroecosystem.
  • Authors:
    • Gunter, C. C.
  • Source: ISHS Acta Horticulturae IV International Symposium on Ecologically Sound Fertilization Strategies for Field Vegetable Production
  • Issue: 852
  • Year: 2010
  • Summary: Efforts are being made to reduce the negative impacts that high intensity vegetable production can have on the soil. Soil nutrient removal and soil compaction due to heavy equipment can lead to long lasting problems in future production cycles. Producers are beginning to look at the beneficial effects that cover crops can have on soil tilth and fertility. Three rotational cover crop areas were established on the Southwest Purdue Agriculture Center in Vincennes, Indiana and each area was divided into four cover crop plots, no-till wheat, clover, oilseed radish and a bare ground control. Processing tomatoes, sweetcorn and snap beans were planted across the four cover crop plots within each rotational area. Two varieties of each type of vegetable were grown in each cover crop. Processing tomatoes had significantly less yield in the no-till wheat cover crop compared to the other three cover crops. There were also a higher proportion of green and turning fruit in that treatment. Snap beans showed significantly higher yields when grown in the oilseed radish and clover cover crops. Sweetcorn had significantly shorter ear length when grown in the no-till wheat cover crop. Varietal differences exist with cover crops, suggesting that some varieties perform better than others when using a specific cover crop.
  • Authors:
    • Singh, B. K.
    • Singh, D. K.
    • Yadav, V. P. S.
    • Singh, L.
  • Source: Indian Research Journal of Extension Education
  • Volume: 10
  • Issue: 3
  • Year: 2010
  • Summary: The cultivation of vegetables, which is done mainly for economic gain or for marketing purpose, is known as Commercial Vegetable Cultivation. India is one of the largest producer of raw materials for the food processing industries in the world (only 2%). The value addition in food sector is as low as 7 percent and will go up to 35 percent. There is need for increasing food processing from 2 percent to 10 percent by 2010 which will be reflected, in the corresponding increase in Gross National Product. Vegetable cultivation has great potentiality and scope for improving socio-economic condition of small and marginal farmers since it provides higher yield and high economic return in short time as compared to food grains. It is an indispensable part of balanced diet and according to Indian Council of Medical Research recommendation; average person should consume nearly 300 g of vegetable daily. Growing of vegetables is 4 to 8 times more remunerative than cereals and it also generate employment in the rural areas. Commercial vegetable cultivation is not getting as popular as it should be among growers because of high input costs, lack of irrigation facilities and difficulties in their marketing and storage. It is estimated that by 2010 country's vegetable demand would be around 135 million tonnes. There is an urgent need to increase the productivity of vegetable in order to provide nutritional security to increasing population of India. Uttar Pradesh is second largest producer state of vegetable. Due to its proximity to National Capital Territory of Delhi, Ghaziabad has a great potential for commercial vegetable cultivation. Hence, the study was carried out in eight blocks of this district. In this study adoption level refers to the level of adoption of recommended cultivation practices of cabbage by the respondents. Fifteen recommended practices included in the package of practices in vegetable cultivation were used for measuring this adoption. The findings of this study highlighted that about 85 percent of the vegetable growers had low or medium adoption of commercial cabbage cultivation practices meaning there by medium adopters were more energetic, knowledgeable, dynamic and having more interest in adopting modern vegetable technologies.
  • Authors:
    • Nutsugah, S. K.
    • Amponsah, N. T.
  • Source: Pakistan Journal of Nematology
  • Volume: 28
  • Issue: 1
  • Year: 2010
  • Summary: Soils and roots of 10 field crops grown in Northern and Upper East Regions of northern Ghana were sampled for the presence of plant parasitic and non-plant-parasitic nematodes. Species belonging to Xiphmema, Longidorus and Hoplolaimus were the most predominant and significantly higher, whereas Tylenchorhynchus was the least common genus of plant parasitic nematodes found. Meloidogyne, Pratylenchus, Heterodera and Hirschmanniella spp. were frequently found associated with soils and roots of tomato, peanut, soybean and irrigated rice respectively. In all, 16 genera of plant parasitic nematodes and eight of non-plant parasitic nematodes were recorded with the most ubiquitous being Cephalobus spp., (non parasitic) in root and soil samples of all the 10 crops irrespective of host location. Findings from the survey however, had provided evidence showing that soils and roots of most major crops grown throughout northern Ghana were infected with several types of parasitic nematodes.
  • Authors:
    • de Cara Garcia, M.
    • Roubtsova, T.
    • Antonio Lopez-Perez, J.
    • Ploeg, Antoon
  • Source: Journal of Nematology
  • Volume: 42
  • Issue: 2
  • Year: 2010
  • Summary: Broccoli (Brassica oleracea), carrot (Daucus carob), marigold (Tagetes patula), nematode-resistant tomato (Solanum lycopersicum), and strawberry (Fragaria ananassa) were grown for three years during the winter in a root-knot nematode (Meloidogyne incognita) infested field in Southern California. Each year in the spring, the tops of all crops were shredded and incorporated in the soil. Amendment with poultry litter was included as a sub-treatment. The soil was then covered with clear plastic for six weeks and M. incognita:susceptible tomato was grown during the summer season. Plastic tarping raised the average soil temperature at 13 cm depth by 7 degrees C. The different winter-grown crops or the poultry litter did not affect M. incognita soil population levels. However, root galling on summer tomato was reduced by 36%, and tomato yields increased by 19% after incorporating broccoli compared to the fallow control. This crop also produced the highest amount of biomass of the five winter-grown crops. Over the three-year trial period, poultry litter increased tomato yields, but did not affect root galling caused by M. incognita. We conclude that cultivation followed by soil incorporation of broccoli reduced M. incognita damage to tomato. This effect is possibly due to delaying or preventing a portion of the nematodes to reach the host roots. We also observed that M. incognita populations did not increase under a host crop during the cool season when soil temperatures remained low (< 18 degrees C).
  • Authors:
    • McSorley, R.
    • Bhan, M.
    • Chase, C. A.
  • Source: Nematropica
  • Volume: 40
  • Issue: 1
  • Year: 2010
  • Summary: Two field experiments were initiated in summer 2006 in north-central Florida to compare the effects of integrating cover crops, living mulches, and intercropping on plant-parasitic nematode populations, as well as the effect of fall and spring vegetables on the multiplication rate of root-knot nematodes. Treatments consisted of seven organic cropping systems that included a summer cover crop followed by fall and spring vegetables. The summer cover crop included: pearl millet (Pennisetum glaucum), sorghum sudangrass (Sorghum bicolor x S. bicolor var. sudanense), sunn hemp (Crotalaria juncea), velvetbean (Mucuna pruriens var. pruriens), weedy fallow, mixture of pearl millet-sunn hemp, and mixture of sorghum sudangrass-velvet bean. One experiment utilized fall yellow squash (Cucurbita pepo) and spring bell pepper (Capsicum annuum) as vegetable crops, and fall broccoli (Brassica oleracea) and spring sweet corn (Zea mays) were used in the other experiment. Nematode populations were monitored at the end of the cover crop and vegetable seasons. Summer cover crops of sorghum-sudangrass or pearl millet increased root-knot nematode (Meloidogyne incognita) population levels in some instances while sunn hemp suppressed it in the broccoli-sweet corn experiment. The multiplication rate of root-knot nematodes was lowest when broccoli was planted in the cropping system. Systems with sorghum-sudangrass (alone or in mixture) increased population densities of ring (Mesocriconema spp.) and lesion (Pratylenchus spp.) nematodes, and occasionally increased stubby-root nematodes (Paratrichodorus spp.). Cover crops that increased nematode numbers when planted alone usually gave the same result when planted in mixtures with another cover crop. Other cropping systems failed to suppress plant-parasitic nematodes but maintained low densities similar to weedy fallow.