• Authors:
    • Wang, Y. M.
    • Mahemujiang, A.
    • Su, L. T.
    • Hudan, T.
    • Mu, H. C.
    • Zhang, J. Z.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 27
  • Issue: 7
  • Year: 2011
  • Summary: Based on measured date in field, the soil salt changes for cotton field with drip irrigation under the plastic mulch were investigated. Through analyzing the salinity changes in cotton field with different irrigation years in four different growing period, it was concluded that salt content in soil depth 0-20 cm was reduced during before planting, seedling stage, and the boll opening period, but increased during the blooming-boiling stage. Salt content in 40-80 cm increased slowly during before sowing and reduced during the blooming period and boll opening period. The accumulation of salt at emitter was less than that at any other position but more at interspace of films in horizontal direction. The accumulation of salt in 0-20 cm of vertical direction reducted, but in the 60-100 cm it was larger. Meanwhile with the drip irrigation time extension, soil salt content would increase, especially in the 60-100 cm, the increasing trend was significant. At the location of emitter, inter-lines and inter-films, the total salt content would increase successively. The zone of 60-100 cm was of largest salt accumulation. In the cotton growth period, the depth of 0-60 cm soil kept desalting state, and the depth of 60-100 cm soil appeared depositing salt state. The results can provide references for management and prevention of drip irrigation water and salt under mulch in arid regions.
  • Authors:
    • Imran, K.
    • Muhammad, A.
    • Muhammad, A.
    • Usman, I.
  • Source: Soil & Environment
  • Volume: 30
  • Issue: 1
  • Year: 2011
  • Summary: The study was conducted with the aim to determine the impact of soil quality on the Bt cotton productivity. A sample of 150 farmers was selected by using multi-stage sampling technique from three districts i.e. Rahim Yar Khan, Multan and Mianwali. A Cobb Douglas production function was employed to assess the effect of various agronomic and demographic variables on the Bt cotton productivity. Results of the analysis indicated that land preparation cost, seed cost, fertilizer cost, labour cost and dummy variable of soil quality were significant and positively contributing towards higher Bt cotton yield. While the spray cost and irrigation cost variable were found positive but non-significant. Findings of the study suggested that focusing on maintaining and improving the quality of soils is necessary to obtain higher crop yields. All this needs attention of agricultural extension department to provide information about advance techniques to farmers for improving soil quality.
  • Authors:
    • Tahir, M. A.
    • Quddus, M. A.
    • Muhammad, A.
    • Muhammad, A.
    • Nighat, F.
  • Source: Pakistani Journal of Agricultural Science
  • Volume: 48
  • Issue: 1
  • Year: 2011
  • Summary: The paper examined the resource use efficiency of small Bt cotton farmers of Punjab province of Pakistan using the production function approach. Data for the study were obtained from 150 randomly selected Bt cotton farmers from Punjab province using a multistage sampling procedure and then categorized into small, medium and large farmers. Average farm size of small farmer was found to be 5 acres. Regression results indicated that Fertilizer, Spray Number, Irrigation acre inch and labour cost were significantly affecting Bt cotton production while farm size was found non significant. The resource use efficiency analysis showed that efficiency ratios i.e. MVP/MFC for inputs fertilizer (Kg), spray number, irrigation (acre inch) and labour cost (Rs) were found to be 1.5, 3.94, 3.01 and 1.27, respectively. All the efficiency ratios, more than unity indicated the under utilization of all the production inputs under consideration in case of small Bt cotton farmers. Bt cotton production for small Bt farmers had an increasing return to scale with elasticity of production 1.27. Opportunities still exists to increase Bt cotton output in the study area by increasing the level of above mentioned productive resources.
  • Authors:
    • Murari, L.
  • Source: Regional Environmental Change
  • Volume: 11
  • Issue: Supplement 1
  • Year: 2011
  • Summary: One of the targets of the United Nations 'Millennium Development Goals' adopted in 2000 is to cut in half the number of people who are suffering from hunger between 1990 and 2015. However, crop yield growth has slowed down in much of the world because of declining investments in agricultural research, irrigation, and rural infrastructure and increasing water scarcity. New challenges to food security are posed by accelerated climatic change. Considerable uncertainties remain as to when, where and how climate change will affect agricultural production. Even less is known about how climate change might influence other aspects that determine food security, such as accessibility of food for various societal groups and the stability of food supply. This paper presents the likely impacts of thermal and hydrological stresses as a consequence of projected climate change in the future potential agriculture productivity in South Asia based on the crop simulation studies with a view to identify critical climate thresholds for sustained food productivity in the region. The study suggests that, on an aggregate level, there might not be a significant impact of global warming on food production of South Asia in the short term (
  • Authors:
    • Romero, R.
    • Duran, V. H.
    • Jimenez, J. A.
    • Garcia-Tejero, I.
    • Muriel,J . L.
    • Hernandez, A.
  • Source: Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: Different strategies of deficit irrigation have been studied in an 11-year old citrus trees ( Citrus sinensis L. Osb. 'Navelina') grafted onto Carrizo citrange ( Citrus sinensis L. Osb. * Poncirus trifoliata L. Raf.). A sustained deficit irrigation (SDI) treatment was established, with a water supplied of 60% of the crop evapotranspiration (ET c); and a low-frequency deficit irrigation treatment (LFDI), watered according to the plant-water status. As a control a full irrigated at 100% of ET c was included. Midday stem water potential (Psi stem), stomatal conductance (g s), and micrometric trunk diameter fluctuations were measured during the maximum evapotranspirative demand period to evaluate the plant-water status, and to establish the main relationships between them. The seasonal pattern of the studied variables had a behavior consistent with the applied irrigation volumes. Significant relationships between Psi stem and g s, and the maximum daily shrinkage (MDS) were found. The lowest Psi stem and g s values were registered in the deficit treatments being the MDS significative higher in these treatments than in the control treatment. Yield response was highly influenced by irrigation strategy, being these results for LFDI significant better than SDI. Considering these results and the significant relationships between MDS and Psi stem, LFDI can be a sustainable deficit irrigation strategy, encouraging significant water savings without important impact on yield and fruit quality.
  • Authors:
    • Amiri, N. A.
    • Kangarshahi, A. A.
    • Namdari, M.
  • Source: AFRICAN JOURNAL OF AGRICULTURAL RESEARCH
  • Volume: 6
  • Issue: 11
  • Year: 2011
  • Summary: In this study, the citrus (orange and mandarin) production in Mazandaran province of Iran and the energy equivalences of input used in this production are investigated. Data in this study was obtained from 110 citrus orchards by a face to face questionnaire method. The results revealed that mandarin production had more energy intensive compared to orange. The major energy inputs in orange and mandarin production were diesel fuel (27 and 24%), chemical fertilizers (22 and 23%) and irrigation water (21 and 23%), respectively. The results showed that 62375.18 MJ ha -1 energy were consumed by orange orchards and 77501.17 MJ ha -1 by mandarin orchards. Energy use efficiency, energy productivity, specific energy, and net energy gain were calculated. The energy use efficiency for orange and mandarin were 0.99 and 0.77, respectively. In average, the non-renewable form of energy input was 67.14% of the total energy input used in citrus production compared to 33.07% for the renewable form. Optimal consumptions of diesel fuel, chemical fertilizers and other major inputs would be useful techniques for decreasing energy consumption in citrus production.
  • Authors:
    • Rodriguez-Moran, M.
    • Garcia-Olmos, B.
    • Andujar, S.
    • Navarro, J. M.
    • Perez-Tornero, O.
    • Morte, A.
  • Source: Acta Horticulturae
  • Issue: 922
  • Year: 2011
  • Summary: Arbuscular mycorrhizal (AM) symbiosis is thought to increase host resistance to salinity stress, a characteristic that could be interesting in areas where the scarcity of irrigation waters forces growers to use low-quality irrigation water. To test this hypothesis seedlings of the rootstocks Mandarin Cleopatra ( Citrus reshni Hort. ex Tan.), Sour orange ( Citrus aurantium (L.)) and Alemow ( Citrus macrophylla Wester) were grown in a growth chamber and inoculated with a mixture of two AM fungi ( Glomus intraradices and Glomus mosseae) (IP), or left non-inoculated (NIP). From forty-five days after fungal inoculation onwards plants were irrigated with nutrient solution containing 50 mM NaCl and, three months after inoculation, the growth, mineral nutrition and physiological response were analysed. AM fungi significantly increased all plant growth parameters studied, especially in the Cleopatra and Alemow rootstocks. In general, plant growth parameters were higher in salinized IP plants than in non-salinized NIP plants, demonstrating that AM colonization compensates for the growth limitations imposed by saline conditions. The water content was higher in IP plants of Cleopatra and Alemow but not in the Sour orange seedlings. Under saline conditions NIP Alemow plants had a strongly-decreased water content, while the water content of IP Alemow plants was similar to that of non-salinised plants. In all three rootstocks, NIP plants showed a greater degree of salt-induced foliar damage and chlorosis than IP plants. Although IP plants were not fertilised with phosphorus in the experiment, they had significantly higher levels of this nutrient in roots, stems and leaves than NIP plants both in salinised and control plants. The beneficial effect of mycorrhization appears to be unrelated with protection against the uptake of excess of Na + or Cl - by the plant. Our findings confirm that AM fungi can alter host responses to salinity stress, improving the P nutrition and diminishing chlorosis and salt damage.
  • Authors:
    • Naderi, M. R.
    • Nayerain-Jazy, A. H.
    • Rezaei, A.
  • Source: RESEARCH ON CROPS
  • Volume: 12
  • Issue: 3
  • Year: 2011
  • Summary: Cotton is one of the most important and strategically crops all over the world especially in Iran which is grown to use both fiber and oil. In improving management of cotton cultivation, irrigation, nutrition and their interaction are very important. So, this study was conducted to evaluate the effect of soil moisture, foliar application of micronutrients and their interaction on yield and quality characteristics of cotton fiber at the Research Farm of Isfahan Islamic Azad University (Khorasgan Branch) in a split plot layout with three replications in 2009. Irrigation treatments based on 80 and 160 mm cumulative evaporation from evaporation pan class A were regarded as the main factor and without, two times and three times foliar application of micronutrients were applied as sub-factor. The traits including unginned cotton (lint+cotton seed) yield, lint yield and some of lint qualitative traits such as mean length, uniformity index, elongation, strength, fineness and short fiber index were calculated and analysis of variance was performed for each one of the traits. The results showed that the effect of irrigation on above all traits was significant at the 1% probability level. Drought stress (irrigation based on 160 mm cumulative evaporation) caused 7% increase in unginned cotton yield. In fact, much moisture stimulated vegetative growth and delayed reproductive development, as a result unginned cotton has decreased. Also, a similar result was obtained about the characteristics above. Three times foliar application of micronutrients than the control increased both unginned cotton and lint yield about 8% and improved all qualitative fiber traits. Maximum and minimum lint yield equal to 87.96 and 73.67 g/m(2) was obtained in association With irrigation based on 80 mm cumulative evaporation with three times foliar application of micronutrients and irrigation based on 160 mm cumulative evaporation without foliar application of micronutrients, respectively.
  • Authors:
    • Bhandary, N. P.
    • Koike, Y.
    • Nishimura, F.
    • Tsuno, H.
  • Source: Journal of Water and Environment Technology
  • Volume: 9
  • Issue: 2
  • Year: 2011
  • Summary: Matsuyama region, located in Shikoku Island, Japan faces the Seto Inland Sea on the west, where the annual rainfall is relatively less than in the other areas in Japan. In such favorable condition, the cultivation of citrus fruits is popular, and there are a large number of small reservoirs for irrigation purposes. The citrus groves are distributed in hilly areas surrounding the paddy fields and residential areas so there are higher chances for the nearby water environment to get affected by leachate from the groves. This paper investigates the water quality characteristics of the leachate from the groves, and studies the changes of the leachate quality near the collecting reservoirs. It was found that the grove soils are highly acidic and the leachate contains metals and nutrients in high concentration. On the other hand, the water quality of the leachate changed after it flowed into the reservoirs, and the concentrations became lower. It is understood that chemical and biological reactions help remove the contaminants in the reservoir, and from the standpoint of self-purification, reservoirs play an important role. This paper also discusses the kinetics of the self-purification and the quantitative estimation based on the experimental results.
  • Authors:
    • Nurzhanovna, A. G.
  • Source: AFRICAN JOURNAL OF AGRICULTURAL RESEARCH
  • Volume: 6
  • Issue: 17
  • Year: 2011
  • Summary: Structural restructuring through opening of industrial associations and introduction of cluster technologies has become possible mainly in most developed industries of the Kazakhstan economy including cotton-textile area. Kazakhstan is situated in the centre of broad markets sales of CIS and Eastern European states, which makes it possible to apply the development model to cluster industry. Resource endowment of cotton-textile industry of Kazakhstan is determined by such components as natural and climatic conditions favourable for cotton plant cultivation along with professional skills of local population, farm field irrigation and manufacturing capacity of cotton processors.