• 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.
  • Authors:
    • Rocha, H. S.
    • Souza, A. P. de
    • Carvalho, D. F. de
    • Lima, M. E. de
    • Guerra, J. G. M.
  • Source: Revista Brasileira de Engenharia Agrícola e Ambiental
  • Volume: 16
  • Issue: 6
  • Year: 2012
  • Summary: This study was carried out in the municipality of Seropedica-RJ, in order to determine, under organic farming and no tillage system, the yield of eggplants under different irrigation depths and cropping systems (intercropped with legumes and alone). The experimental design was in randomized blocks in a split plot design with four replications. The plots were characterized by the treatments corresponding to different water depths (40, 70, 100, 120% ETc), and the sub plots, the intercropping systems with cowpea and eggplant alone. Cropping systems did not influence the final yield of eggplant. However, considering the different irrigation depths, the highest commercial yield (65.41 Mg ha -1) was obtained for a total depth of 690.04 mm (106.8% ETc). The lower applied depth provided lower quality of fruit compared with that observed in the higher depths. The rate of fruit discard was 3 and 14%, respectively, for the higher and lower depths of irrigation.
  • 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.
  • Authors:
    • Oweis, T.
    • Karrou, M.
  • Source: Agricultural Water Management
  • Volume: 107
  • Year: 2012
  • Summary: Selecting appropriate crops and applying deficit irrigation can help increase water productivity in water-limited regions such as the Mediterranean. The objective of this study was to develop water production functions of major cereal and legume crops under the same environmental and management conditions. Bread and durum wheat, faba bean, chickpea, and lentil were grown under full supplemental irrigation (FSI), two deficit irrigations levels of 2/3 of FSI (2/3SI) and 1/3 of FSI (1/3SI), and under rainfed conditions (no irrigation). In average, the actual evapotranspirations (ETs) under FSI were 549, 552, 365, 451 and 297 mm, for bread wheat, durum wheat, faba bean, chickpea and lentil, respectively. For the same crops, they were 463, 458, 330, 393 and 277 mm for the treatment 2/3SI and 357, 351, 265, 318 and 244 mm for the treatment 1/3SI, respectively. In the case of the rainfed treatment, ETs for the mentioned crops were 250, 251, 227, 237 and 215 mm, respectively. The experiment was conducted at the ICARDA experimental station at Tel Hadya, near Aleppo, Syria, over three growing seasons from 2007 to 2010. Results showed that, in general, the treatment with 1/3 of FSI gave the highest rate of increase in grain yield and water productivity. The mean grain yield from rainfed, 1/3SI, 2/3SI, and FSI were 1.36, 3.82, 5.18, and 5.70 t/ha for bread wheat; 1.24, 3.80, 5.10, and 5.75 t/ha for durum wheat; 1.57, 2.35, 2.86, and 3.54 t/ha for faba bean, 1.36, 2.63, 3.36, and 3.74 t/ha for chickpea, and 0.64, 1.16, 1.42, and 1.58 t/ha for lentil respectively. Grain yield reductions due to the application of 2/3SI were around 10, 5, 15.6, and 10.2% of FSI on average for wheat, chickpea, faba bean, and lentils, respectively. Deficit irrigation at 2/3SI increased water productivity compared to rainfed treatments, by 200, 223, 126, 148 and 190% for bread wheat, durum wheat, faba bean, chickpea, and lentils, respectively. However, differences in total water productivity of crops grown under full irrigation compared to deficit irrigation were not significant. Irrigation water productivity ranged from 25 kg ha -1 mm -1 in wheat with 1/3SI to 10 kg ha -1 mm -1 for legumes under the FSI treatment. Unlike legumes, maximizing wheat grain yield caused a decline in water productivity.
  • Authors:
    • Bansal, M.
    • Dudeja, S. S.
    • Kukreja, K.
  • Source: African Journal of Microbiology Research
  • Volume: 6
  • Issue: 21
  • Year: 2012
  • Summary: Thirty-four roots and rhizospheric soil samples of seven kharif and eight rabi season crops were collected from different areas of the university farm. The percent Arbuscular mycorrhizal (AM) fungal infection in different crops ranged from 0 to 100%. Maximum AM fungal colonization (100%) was found in cowpea, chickpea and pea and minimum in urdbean, soybean, barley and even in chickpea (20 to 30%). Barley, tomato and few samples of mustard and wheat also did not show any AM fungal infection. The number of spores per 50 g of soil ranged from 0 to 925 in kharif season crops and 25 to 1150 in rabi season crops. Maximum number of AM fungi spores was found in the rhizospheric soil of sorghum with 925 spores 50 gm -1 of soil and minimum in case of cotton with 25 spores 50 gm -1 of soil, while no spores were found in case of pigeonpea and urdbean field soils. In case of rabi crops maximum numbers of AM fungal spores were found in the rhizospheric soil of mustard and wheat with 1150 spores 50 gm -1 of soil. On the basis of pattern of infection and spore morphology the AM genera identified was Glomus in kharif season crops and Glomus, Scutellospora, Acaulospora in rabi season crops. In few samples the external hyphae and clusters were identified as Glomus versiforme. The predominant genus identified was Glomus in university farm soils.
  • Authors:
    • Twomlow, S.
    • Mupangwa, W.
    • Walker, S.
  • Source: Field Crops Research
  • Volume: 132
  • Year: 2012
  • Summary: Proponents of conservation agriculture (CA) argue that the CA approach offers the greatest opportunity to increase the productivity in smallholder agro-ecosystems. This study was designed to assess (1) first year maize, cowpea and sorghum yield responses to a combination of reduced tillage and mulching and (2) maize yield responses to rotation with cowpea and sorghum in reduced tillage systems. Two conservation tillage methods (ripping and planting basins) combined factorially with seven mulch levels (0, 0.5, 1, 2, 4, 8 and 10 t ha -1) were compared with conventional mouldboard ploughing. The experiment was run for four consecutive growing seasons allowing for a rotation of maize, cowpea, sorghum and maize in some fields used in the study. Crop yields were determined across all tillage and mulch combinations in each year. Tillage system had no significant effect on maize yield while maize grain yield increased with increase in mulch cover in seasons that had below average rainfall. Mulching at 2-4 t ha -1 gave optimum yields in seasons with below average rainfall. Tillage system and mulching had no significant effect on cowpea yield when soil moisture was not limiting. However, the ripper and basin systems had 142 and 102% more cowpea grain than the conventional system in 2006/2007 because of differences in planting dates used in three systems and poor rainfall distribution. The conventional and ripper systems gave 26 and 38% more sorghum grain than the basin system. Rotating maize with cowpea and sorghum resulted in 114, 123 and 9% more grain than first year maize, maize-maize monocrop and maize-cowpea-maize in the conventional system. In the ripper system, maize-cowpea-sorghum-maize rotation gave 98, 153 and 39% more grain than first year maize, maize-maize monocrop and maize-cowpea-maize rotation. In the basin system, maize-cowpea-sorghum-maize rotation gave 274, 240 and 43% more grain than first year maize, maize-maize monocrop and maize-cowpea-maize rotation. However, long term studies under different soil, climatic and socio-economic conditions still need to be conducted to substantiate the observations made in the reported study.
  • Authors:
    • Mkwinda, S.
    • Aune,J. B.
    • Ngwira, A. R.
  • Source: Field Crops Research
  • Volume: 132
  • Year: 2012
  • Summary: Low crop yields due to continuous monocropping and deteriorating soil health in smallholder farmers' fields of sub-Saharan Africa have led to a quest for sustainable production practices with greater resource use efficiency. The aim of the study was to elucidate the short term effects of conservation agriculture (CA) systems on soil quality, crop productivity and profitability. In Balaka market and Ntonda sections of Manjawira Extension Planning Area (EPA), in Ntcheu district, central Malawi, we compared continuous monocropped maize (Zea mays) under conventional tillage practice (CP) with different CA systems in continuous monocropped maize (CAM) and intercropping with pigeonpea (Cajanus cajan) (CAMP), Mucuna pruriens (CAMM), and Lablab purpureus (L) (Sweet) (CAML). The study was conducted from 2008 to 2011 in 72 plots in 24 farmers' fields. In Balaka market section CA plots with maize + legumes produced up to 4.3 Mg ha(-1) of vegetative biomass against 3.5 Mg ha for maize alone in CP. In Ntonda section CA plots with maize + legumes produced up to 4.6 Mg ha(-1) of vegetative biomass against 2.4 Mg ha(-1) for maize alone in CP. In both sections, during the entire study period. CA did not have a negative effect on crop yields. During the drier seasons of 2009110 and 2010/11, CA had a positive effect on maize grain yield at both sites (average yield of 4.4 and 3.3 Mg ha(-1) in CA and CP respectively). However, associating maize with legumes reduced maize yields compared to CAM particularly in drier years of 2009-10 and 2010-11. Farmers spent at most 47 days ha(-1) producing maize under CA systems compared to 65 days ha(-1) spent under conventional tillage practices. However, total variable costs were higher in CA systems compared to conventional practice (at most US$416 versus US$344 ha(-1)). CAMP resulted in more than double gross margin compared to CPM (US$705 versus uS$344 hat). Infiltration estimated as time to pond was highest in CA maize legume intercrops (8.1 s) than CP (6.8 s). Although it was not feasible to directly estimate effects on water balances of these farmer-managed experiments, it can be assumed that the yield differences between CA and CP could be attributed to tillage and crop residue cover since other farm operations were generally the same. Intercropping maize and pigeonpea under CA presents a win-win scenario due to crop yield improvement and attractive economic returns provided future prices of maize and pigeonpea grain remain favourable. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Shah, S. C.
    • Chen, Z. S.
    • Adhikari, K. R.
    • Ghimire, R.
    • Dahal, K. R.
  • Source: Paddy and Water Environment
  • Volume: 10
  • Issue: 2
  • Year: 2012
  • Summary: Despite being a major domain of global food supply, rice-wheat cropping system is questioned for its contribution to carbon flux. Enhancing the organic carbon pool in this system is therefore necessary to reduce environmental degradation and maintain agricultural productivity. A field experiment (November 2002-March 2006) evaluated the effects of soil management practices such as tillage, crop residue, and timing of nitrogen (N) application on soil organic carbon (SOC) sequestration in the lowland of Chitwan Valley of Nepal. Rice ( Oryza sativa L.) and wheat ( Triticum aestivum L.) were grown in rotation adding 12 Mg ha -1 y -1 of field-dried residue. Mung-bean ( Vigna radiata L.) was grown as a cover crop between the wheat and the rice. Timing of N application based on leaf color chart method was compared with recommended method of N application. At the end of the experiment SOC sequestration was quantified for five depths within 50 cm of soil profile. The difference in SOC sequestration between methods of N application was not apparent. However, soils sequestered significantly higher amount of SOC in the whole profile (0-50 cm soil depth) with more pronounced effect seen at 0-15 cm soil depth under no-tillage as compared with the SOC under conventional tillage. Crop residues added to no-tillage soils outperformed other treatment interactions. It is concluded that a rice-wheat system would serve as a greater sink of organic carbon with residue application under no-tillage system than with or without residue application when compared to the conventional tillage system in this condition.
  • Authors:
    • Cai, L.
    • Padovan, B.
    • Lee, B.
    • Ren, Y. L.
  • Source: Pest Management Science
  • Volume: 68
  • Issue: 2
  • Year: 2012
  • Summary: BACKGROUND: Methyl bromide is being phased out for use on stored commodities, as it is listed as an ozone-depleting substance, and phosphine is the fumigant widely used on grains. However, phosphine resistance occurs worldwide, and phosphine fumigation requires a long exposure period and temperatures of > 15 degrees C. There is an urgent requirement for the development of a fumigant that kills insects quickly and for phosphine resistance management. This paper reports on a new fumigant formulation of 95% ethyl formate plus 5% methyl isothiocyanate as an alternative fumigant for stored grains. RESULTS: The formulation is stable for at least 4 months of storage at 45 degrees C. A laboratory bioassaywith the formulation showed that it controlled all stages of Sitophilusoryzae (L.), Sitophilusgranarius (L.), Tribolium castaneum (Herbst), Rhyzopertha dominica (F.), Trogoderma variabile Ballion and Callosobruchus maculatus (Fabricius) in infestedwheat, barley, oats and peas at 80 mg L-1 for 5 days, and in canola at both 40mg L-1 for 5 days and 80mg L-1 for 2 days at 25 +/- 2 degrees C. After an 8-14 day holding period, residues of ethyl formate and methyl isothiocyanate in wheat, barley, peas and canola were below the experimental permit levels of 1.0 and 0.1 mg kg(-1). However, fumigated oats needed an 18 day holding period. CONCLUSIONS: The findings suggest that the ethyl formate plusmethyl isothiocyanate formulation has potential as a fumigant for the control of stored-grain insect pests in various commodities. (C) 2011 Society of Chemical Industry
  • Authors:
    • Marins, A. C. de
    • Souza, S. N. M. de
    • Santos, R. F.
    • Veloso, G.
    • Secco, D.
    • Rosa, H. A.
    • Borsoi, A.
  • Source: Food, Agriculture and Environment (JFAE)
  • Volume: 10
  • Issue: 2 part 3
  • Year: 2012
  • Summary: Certain soil physical characteristics such as resistance to penetration (Rs) and bulk density (Ds) are extremely important, and are also indicators of the soil structural quality. This paper aims at evaluating the use of four cover crop species in the reduction of density and soil resistance to penetration in areas where a no-till farming system is applied. The so-called "regenerator" species, which act in soil structure, were considered treatments, and consisted of four species: showy rattlebox ( Crotalaria spectabilis), moha grass ( Setaria italica), pigeon pea ( Cajanus cajan), sorghum ( Sorghum bicolor), and yet the control (an area without crops). Soil bulk density evaluations were carried out according to the methodology recommended by EMBRAPA, in the following depths: 0.0-0.1, 0.1-0.2 and 0.2-0.3 m. Sampling was carried out with five replications for the crop row and five for the spacing between each crop row, in each experimental unit (5 m * 5 m), up to 0.40 m in depth. An experimental design was 5*4*2 factorial, meaning 5 treatments, 4 depths and 2 sampling conditions. The species studied, especially the pigeon pea and the sorghum, showed a great potential to improve soil structural state, for they showed figures to Ds and Rs that were lower than the ones from the area without crops.