11. Heavy metals health risk assessment for population via consumption of food crops and fruits in Owerri, South Eastern, Nigeria.

• Authors:
  • Amadi, C. N.
  • Nduka, J. K.
  • Orisakwe, O. E.
  • Dike, D. O.
  • Bede, O.
• Source: Chemistry Central Journal
• Volume: 6
• Issue: 77
• Year: 2012
• Summary: Background: This study assessed lead, cadmium, and nickel level in food crops, fruits and soil samples from Ohaji and Umuagwo and Owerri in South Eastern Nigeria and estimated the potential health risks of metals. Samples were washed, oven-dried at 70-80°C for 24 h and powdered. Samples were digested with perchloric acid and nitric acid. Metals were analysed with Unicam Atomic Absorption Spectrophotometer. Result: The concentration of Pb, Cd, and Ni in Ohaji exceeded the maximum allowable concentrations for agricultural soil as recommended by EU. Lead, Cd, and Ni in the food crops were highest in Oryza sativa, Glycine max, and Pentabacta microfila respectively. Highest levels of Pb, Cd, and Ni, in fruits were detected in Canarium schweinfurthii, Citrus reticulata, Ananas comosus respectively. The true lead and cadmium intake for the rice based meal were 3.53 and 0.034 g/kg respectively. Whereas the true intake of lead and cadmium for the cassava based meal were 19.42 and 0.049 g/kg respectively. Conclusion: Local food stuff commonly available in South Eastern Nigeria villages may contribute to the body burden of heavy metal. This is of public health importance.

12. Effects of drip irrigation regimes and basin irrigation on Nagpur mandarin agronomical and physiological performance.

• Authors:
  • Huchche, A. D.
  • Srivastava, A. K.
  • Panigrahi, P.
• Source: Agricultural Water Management
• Volume: 104
• Year: 2012
• Summary: The scarcity of irrigation water is one of the major causes of low productivity and decline of citrus orchards. The present study was planned with a hypothesis that the drip irrigation (DI) could save a substantial amount of water over surface irrigation, besides improving the yield of citrus plants. The experiment was conducted for 3 seasons during 2006-2009, with 'Nagpur' mandarin ( Citrus reticulata Blanco) plants budded on rough lemon ( Citrus Jambhiri Lush) rootstock in central India. The effects of DI and basin irrigation (BI) on soil chemical properties and crop responses were studied. DI was scheduled every-other-day at 40%, 60%, 80% and 100% of the alternate day cumulative evaporation ( Ecp) measured in Class-A evaporation pan. DI except irrigation at 40% Ecp proved superior to BI, producing more growth and fruit yield of plants. The higher plant growth was recorded with higher regime of DI. The maximum fruit yield in DI at 80% Ecp, using 29% less irrigation water resulted in 111% improvement in irrigation water productivity under this treatment over BI. The heavier fruits, with lower acidity and higher total soluble solids, were harvested in DI at 80% Ecp compared with BI. The significant variation of soil water content at 0-0.2 m depth under DI indicated the confinement of effective root zone of the plants in top 0.2 m soil. The maximum rate of net-photosynthesis, stomatal conductance and transpiration in leafs was recorded in DI at 100% Ecp. However, the plants under DI at 80% Ecp exhibited the highest leaf water use efficiency. The maximum salinity build-up with highest decrease in pH was observed in 0-0.2 m soil under DI, whereas the salinity development was prominent in 0.4-0.6 m soil with an increase in pH under BI. The gain in available macronutrients (N, P and K) and loss of micronutrients (Fe, Mn, Cu and Zn) in soil followed the similar trend of EC. The leaf nutrient (N, P, K, Fe, Mn, Cu and Zn) analysis revealed that DI produced significantly ( P

13. Plant nutrition in response to drip versus basin irrigation in young 'Nagpur' mandarin on inceptisol.

• Authors:
  • Huchche, A. D.
  • Srivastava, A. K.
  • Panigrahi, P.
  • Singh, S.
• Source: Journal of Plant Nutrition
• Volume: 35
• Issue: 2
• Year: 2012
• Summary: Evaluation of drip irrigation treatments scheduled at 40, 60, 80, and 100% of alternate day cumulative pan evaporation (Ecp) against basin irrigation method was undertaken in 1-year-old 'Nagpur' mandarin ( Citrus reticulata Blanco) trees budded on rough lemon [ Citrus jambhiri (L)] rootstock on an alkaline Inceptisol soil type for three seasons during 2003-2005. Growth responses showed significantly ( P≤0.05) higher annual increase in tree height (0.44-0.50 m), scion girth (37-45 mm), and canopy volume (0.508-0.986 m 3) under drip-irrigation except irrigation at 40% Ecp, compared to tree height (0.40 m), scion girth (36 mm), and canopy volume (0.463 m 3) under basin irrigation. The highest magnitude of increase in different growth parameters was observed with drip irrigation at 80% Ecp, which produced the net water saving of 32% over basin irrigation method. Response on leaf nutrient composition under drip irrigation at 80% Ecp likewise produced the similar response, [2.27% nitrogen (N), 1.98% potassium (K), and 121.8 ppm iron (Fe)], significantly ( P≤0.05) higher than under basin irrigation (1.12% N, 1.04% K, and 98.3 ppm Fe), with other nutrients, e.g., phosphorus (P), manganese (Mn), copper (Cu), and zinc (Zn) remained unaffected.

14. Optimal irrigation regime and soil moisture dynamics of cotton crop in Vidarbha region of Maharashtra.

• Authors:
  • Parhad, V. N.
  • Ramamurthy, V.
  • Patil, N. G.
• Source: Journal of Cotton Research and Development
• Volume: 26
• Issue: 1
• Year: 2012
• Summary: An experiment was conducted on farmer's field to observe the effects of different drip irrigation regimes on water use efficiencies (WUE) and soil moisture status for cotton variety NHH44 in Vidarbha region during 2001 and 2002. Treatments were based on open pan evaporation approach. The highest cotton yield was obtained from the least irrigation treatment (T 1). WUE ranged from 0.02 kg/ha/mm in the treatment T 5 to 0.34 kg/ha/mm in T 1. The greatest irrigation water use efficiency (IWUE) was observed in treatment T 1 (2.26 kg/ha/mm), and the smallest IWUE was in treatment T 5 (0.18 kg/ha/mm) in the experimental years, indicating saving of more than 58 per cent irrigation water. Soil moisture status was below 50 per cent of available water capacity (AWC) for 105 days in 2001 as compared to 135 days in 2002 in T 1 implying that light irrigations in place of 6 cm for the clay soils in this part would be preferable and drainage of excess rainwater could be critical to improve yields.

15. Nutrients and nonessential elements in soil after 11 years of wastewater irrigation.

• Authors:
  • Montes, C. R.
  • Stoffella, P. J.
  • He, Z. L.
  • Pereira, B. F. F.
  • Melfi, A. J.
  • Baligar, V. C.
• Source: Journal of Environmental Quality
• Volume: 41
• Issue: 3
• Year: 2012
• Summary: Irrigation of citrus ( Citrus aurantium L. * Citrus paradise Macf.) with urban reclaimed wastewater (RWW) can be economical and conserve fresh water. However, concerns remain regarding its deleterious effects on soil quality. We investigated the ionic speciation (ISP) of RWW and potential impacts of 11 yr of irrigation with RWW on soil quality, compared with well-water (WW) irrigation. Most of nutrients (~53-99%) in RWW are free ionic species and readily available for plant uptake, such as: NH 4+, NO 3-, K +, Ca 2+, Mg 2+, SO 42-, H 3BO 3, Cl -, Fe 2+, Mn 2+, Zn 2+, Co 2+, and Ni 2+, whereas more than about 80% of Cu, Cr, Pb, and Al are complexed with CO 3-, OH -, and/or organic matter. The RWW irrigation increased the availability and total concentrations of nutrients and nonessential elements, and soil salinity and sodicity by two to three times compared with WW-irrigated soils. Although RWW irrigation changed many soil parameters, no difference in citrus yield was observed. The risk of negative impacts from RWW irrigation on soil quality appears to be minimal because of: (i) adequate quality of RWW, according to USEPA limits; (ii) low concentrations of metals in soil after 11 yr of irrigation with RWW; and (iii) rapid leaching of salts in RWW-irrigated soil during the rainy season.

16. Evaluation of potato cultivars against arsenic accumulation under an arsenic-contaminated zone of eastern India.

• Authors:
  • Sukanta, P.
  • Aparajita, M.
  • Rajib, K.
• Source: Potato Journal
• Volume: 39
• Issue: 1
• Year: 2012
• Summary: A field experiment was undertaken to evaluate the varietal tolerance and accumulation of arsenic by different potato cultivars at village Nonaghata in Nadia district of West Bengal during winter season of 2008-09 and 2009-10. Arsenic content in the irrigation water was 0.094 to 0.108 mg/l. Arsenic accumulation of different plant parts was in the following sequence: root > stem > leaf > tuber, irrespective of all cultivars. After harvesting, the least arsenic loading was observed in cultivar Kufri Jyoti (0.05 mg/kg) which also showed the highest productivity (32.32 t/ha). Cultivar Kufri Chandramukhi and locally grown variety Lal alu accumulated a lesser amount of arsenic and had also a higher yield compared with the other entries.

17. Partial root drying as strategy for water use optimization in a 'Tahiti' lime orchard under the semi-arid of Bahia State.

• Authors:
  • Santana, J. A. D. V.
  • Carvalho, G. C.
  • Machado, V. V.
  • Daniel, R.
  • Coelho, E. F.
  • Coelho Filho, M. A.
  • Sampaio, A. H. R.
  • Santana Junior, E. B.
• Source: Acta Horticulturae
• Issue: 928
• Year: 2012
• Summary: The management of irrigation using partial root drying (PRD) was tested in an orchard of 'Tahiti' lime in the semi-arid conditions of Iacu, BA. Six treatments were evaluated: T1, T2, T3 (50% ETc PRD) with plants irrigated by a microsprinklers with its position alternating every 7, 14 or 21 days, respectively, and wetting on opposite sides of the root system; T4 (DI 50% ETc) irrigation was fixed on one side using one emitter per plant, T5 (100% ETc) was the control treatment using two microsprinklers per plant in a fixed position. In T6, at each interval of 21 days, one and two micro-sprinklers were alternatively used per plant. Results demonstrated significant differences in fruit production by the Scott Knott test (p

18. Effect of Reduced Tillage and Mineral Fertilizer Application on Maize and Soybean Productivity

• Authors:
  • Okeyo, J.
  • Vanlauwe, B.
  • Kimetu, J. M.
  • Waswa, B.
  • Bationo, A.
  • Kihara, J.
  • Mukalama, J.
  • Martius, C.
• Source: Experimental Agriculture
• Volume: 48
• Issue: 2
• Year: 2012
• Summary: Reduced tillage is said to be one of the potential ways to reverse land degradation and ultimately increase the productivity of degrading soils of Africa. We hypothesised that crop yield following a modest application of 2 t ha(-1) of crop residue in a reduced tillage system is similar to the yield obtained from a conventional tillage system, and that incorporation of legumes in a cropping system leads to greater economic benefits as opposed to a cropping system involving continuous maize. Three cropping systems (continuous maize monocropping, legume/maize intercropping and rotation) under different tillage and residue management systems were tested in sub-humid western Kenya over 10 seasons. While soybean performed equally well in both tillage systems throughout, maize yield was lower in reduced than conventional tillage during the first five seasons but no significant differences were observed after season 6. Likewise, with crop residue application, yields in conventional and reduced tillage systems are comparable after season 6. Nitrogen and phosphorus increased yield by up to 100% compared with control. Gross margins were not significantly different among the cropping systems being only 6 to 39% more in the legume-cereal systems relative to similar treatments in continuous cereal monocropping system. After 10 seasons of reduced tillage production, the economic benefits for our cropping systems are still not attractive for a switch from the conventional to reduced tillage.

19. Conservation agriculture in Laos: Diffusion and determinants for adoption of direct seeding mulch-based cropping systems in smallholder agriculture

• Authors:
  • Tivet, F.
  • Khamxaykhay, C.
  • Rattanatray, B.
  • Jullien, F.
  • Quoc, H. T.
  • Lestrelin, G.
• Source: Renewable Agriculture and Food Systems
• Volume: 27
• Issue: 1
• Year: 2012
• Summary: Over the past half-century, major efforts have been made worldwide to develop sustainable alternatives to agricultural tillage. In line with these efforts, two main research development initiatives have supported the experimentation and dissemination of conservation agriculture (CA) in Laos. Here we present the results of a 4-year monitoring and evaluation study conducted in 21 villages targeted for dissemination. In a context of rapid transition to intensive commercial agriculture in Laos, CA has become an important constituent of agricultural landscapes. However, there are significant variations in adoption rates across the study region. Statistical and qualitative evidence suggests that experimentation and adoption are not contingent upon farm-level variables such as capital, labor, age and education. While access to land helps shape local decision-making, the land tenure threshold under which farmers are not willing to experiment with alternative cropping systems is relatively low and highly variable in both space and time. Rather, experience and awareness of land degradation, production costs, social cohesion and leadership appear to be key factors in explaining most variations in local adoption rates. These results indicate that the practice of CA is not necessarily incompatible with smallholder farming. However, while complex crop associations and rotations are necessary for integrated weed control and reduced chemical use, their diffusion would require a broader transformation of the agricultural industry and the current market demand.

20. Study on agronomically and economically dominant cropping patterns in some selected areas of Barisal District.

• Authors:
  • Kabir, M. J.
  • Islam, M. M.
• Source: Bangladesh Journal of Agricultural Research
• Volume: 37
• Issue: 1
• Year: 2012
• Summary: The study area was Shanuhar village of Babugonj Upazila of Barisal district, which was selected purposively based on agronomic suitability of growing Rabi crops. Necessary data were collected through focus group discussion (FGD) with 30 farmers including small, medium, and large farm households, school teachers, village leaders all the remaining by using pre design check list and structure schedule during May 2007 considering Rabi season of 2006-2007. Usually, farmers of the village could not sow their crops within the optimum time. They transplanted Aman rice in late due to inundation of land and planting of Rabi crops in late because of land unsuitability and long duration of T. Aman rice. Boro rice was adopted about 75% of the cropped area in Rabi season and but yield was low because of inadequate irrigation facilities. In contrast wheat needs comparatively less irrigation than Boro rice. Moreover, mungbean, mustard, lentil and grass pea produce reasonability good yield in rainfed condition. About 20-25% land become suitable for seeding wheat by first week of December after harvesting NfV T. Aman which indicated good prospect of growing wheat in the study village. Wheat is a more profitable Rabi crop than other crops like grass pea, mustard, lentil. Farmers earned the highest per hectare gross return (Tk.98646) and gross margin (Tk.22870) from the Wheat - Aus rice - T. Aman rice pattern whereas Boro rice - Fallow - T. Aman pattern produced the lowest gross return (Tk.65918) and gross margin (Tk.10134). Higher benefit was achieved from the pattern Wheat - Aus rice - T. Aman rice because of less production cost and high price of wheat grain, though three cereals crops could exhaust soil nutrient so that Mungbean-Aus rice - T. Aman pattern may be alternate option to sustain soil health as well as productivity of the selected area.