• Authors:
    • Iqbal, K.
    • Khurshid, W.
    • Hassan, I.
  • Source: Journal of Agricultural Research
  • Volume: 50
  • Issue: 1
  • Year: 2012
  • Summary: A study was conducted during the year 2009 to find out the factors responsible for decline in guava ( Psidium guajava) yield. For this purpose three districts Sheikhupura, Kasur and Faisalabad, Pakistan were selected being core area for guava cultivation. To examine impact of various inputs on guava production, the Cobb-Douglas production function model was used. Factors which caused decline in guava yield were found to be physical beating of flowers, excessive intercropping and number of sprays. The physical beating of flowers (-0.317 coefficient value) and intercropping (-0.200) proved as two major depressing factors. Intercropping in both summer and winter seasons went in a long way in depressing yields. Flower shedding by beating with clubs proved to be more significant (-0.317). It was found that productivity decline can be arrested as well as be reversed with adequate number of irrigations, proper use of fertilizers and adopting good management measures.
  • Authors:
    • Nariya, J. N.
    • Khanpara, M. D.
    • Butani, A. M.
    • Kapadiya, H. J.
  • Source: Journal of Cotton Research and Development
  • Volume: 26
  • Issue: 1
  • Year: 2012
  • Summary: FLD's with participation of farmers' in production technology was conducted in seven districts of Saurashtra. Thirty four, 50 and 50 farmers were selected for FLD's during 2005-2006, 2006-2007 and 2007-2008, respectively. Varietal, fertilizer, irrigation and inter cropping components were conducted in FLD's. Results indicated that 8.83 per cent average seed cotton yield was increased over improved varieties. In fertilizer components, there was no effect of DAP on seed cotton yield, however without DAP clearly showed the average saving of Rs. 1743/ha. The reduction of 3.98 per cent seed cotton yield was recorded in alternate furrow irrigation, but the cost of cultivation of Rs. 3370/ha was decreased as compared to local practices. In inter cropping practices, 10.13 per cent seed cotton yield was increased over local practices. Overall results clearly indicated that an additional net return of Rs. 5130, 3831, 1002 and 859 was recorded in improved varities, intercropping, irrigation and fertilizer components, respectively. Looking to the over all of three years average results with four improved production technologies of FLD's, recorded a increase of 4.6 per cent in seed cotton yield, reduced by 3.12 per cent in cost of cultivation and increased net return of 9.95 per cent with a net profit of 3371 Rs/ha during three years of cropping season.
  • Authors:
    • Takebe, M.
    • Karasawa, T.
  • Source: Plant and Soil
  • Volume: 353
  • Issue: 1-2
  • Year: 2012
  • Summary: Aims A field experiment was conducted where maintenance of indigenous arbuscular mycorrhizal (AM) fungal populations was attempted using AM host cover crops arranged temporally or spatially during growth of nonmycorrhizal crops. Methods To arrange AM hosts temporally, sunflower or oat was grown as a cover crop after non-host cropping (cabbage) or fallowing. In order to arrange AM hosts spatially, red clover, white clover or vetch was intercropped during growth of non-host cabbage. Results The AM colonization and growth of maize with previously introduced sunflower or oat were much greater than those without introduction of cover crops or those with introduction of non-host cover crops. The AM colonization and yield of winter wheat grown after cabbage with AM host intercropping were greater than those after cabbage only cropping, suggesting that arrangement of AM hosts between cabbage rows is effective for maintaining the AM fungal population in soil during non-host cropping. Conclusions Mycorrhizal hosts cropped after or during non-host cropping is an effective means to increase indigenous AM fungal populations. The results show that AM colonization, P uptake and productivity of crops after cultivation of nonmycorrhizal crops can be improved by arranging AM hosts temporally or spatially as cover crops.
  • 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:
    • Kutu, F. R.
  • Source: African Journal of Agricultural Research
  • Volume: 7
  • Issue: 26
  • Year: 2012
  • Summary: Conservation agriculture experiment was conducted under irrigated and dryland conditions during 2007/2008-summer cropping season to determine a suitable soil-crop management practice for increase maize yield. The study consisted of tillage practices (conventional, minimum and zero), cropping systems (sole and intercrop plots) and fertilizer regimes (unfertilized control, low, adjusted low and optimum) as treatments. Minimum and zero tillage practices constituted the conservation agriculture tillage practices while supplementation of low fertilizer rate with seed inoculation using growth enhancing microbial inoculant constituted the adjusted low fertilizer rate. Fertilizer application gave a significant (P
  • Authors:
    • Mariga, I. K.
    • Molatudi, R. L.
  • Source: African Journal of Agricultural Research
  • Volume: 7
  • Issue: 20
  • Year: 2012
  • Summary: An experiment was conducted under dryland conditions at the University of Limpopo experimental farm at Syferkuil in Capricorn district in 2007/2008 and 2008/2009 growing seasons to determine the effect of maize density and dry bean variety on maize/bean intercrop performance. The trial was at 2*2*2 factorial consisting of eight treatments: two maize densities (24 700 and 37 000 plants/ha), two dry bean varieties (small white haricot and red speckled sugar bean) and two cropping systems (sole cropping and intercropping). Open pollinated maize variety ZM 523 (ex CIMMYT) was used in the trial. The results showed that maize density of 24 700 plants/ha yielded lower maize grain than the recommended 37 000 plants/ha and maize grain yields in sole cropping were significantly higher than in intercropping in both growing seasons. Intercropping of maize with red speckled sugar bean resulted in lower grain yield than intercropping of maize with small white haricot in both seasons. Increasing maize density to 37 000 plants/ha reduced number of branches per plant and grain yield of dry bean in both seasons. Sole cropping produced the highest dry bean grain yield component values. Intercropping maize and beans was advantageous at the different bean variety x maize density combinations with all, except one, achieving Land equivalent ratio (LER) values greater than 1. Intercropping of maize plant density of 37 000 plants/ha with red speckled sugar bean gave the highest total LER value in 2007/8 season but less than 1 in 2008/9 season. Intercropping was more advantageous than sole cropping in this study. The highest monetary values were achieved by the bean sole crops and their intercrops with 24 700 plants/ha maize. In this study maize densities of 37 000 plants/ha and 24 700 plants/ha were found to be suitable for sole maize and maize/bean intercropping, respectively.
  • 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:
    • Dresboll, D. B.
    • Thorup-Kristensen, K.
    • Kristensen, H. L.
  • Source: European Journal of Agronomy
  • Volume: 37
  • Issue: 1
  • Year: 2012
  • Summary: One of the core ideas behind organic production is that cropping systems should be less dependent on import of resources, and minimize negative effects on the surrounding environment compared to conventional production. However, even when clearly complying with regulations for organic production, it is not always obvious that these goals are reached. As an example, strong dependence on import of manure is often seen in current organic production, especially in systems producing high value crops such as vegetable crops. The aim of the present study was to test novel approaches to organic rotations, designed to reduce the reliance on import of external resources significantly. We compared a conventional system (C) and an organic system relying on manure import for soil fertility (O1) to two novel systems (O2 and O3) all based on the same crop rotation. The O2 and O3 systems represented new versions of the organic rotation, both relying on green manures and catch crops grown during the autumn after the main crop as their main source of soil fertility, and the O3 system further leaving rows of the green manures to grow as intercrops between vegetable rows to improve the conditions for biodiversity and natural pest regulation in the crops. Reliance on resource import to the systems differed, with average annual import of nitrogen fertilizers of 149, 85, 25 and 25 kg N ha(-1) in the C, O1, O2 and O3 systems, respectively. As expected, the crop yields were lower in the organic system. It differed strongly among crop species, but on average the organic crops yielded c. 82% of conventional yields in all three organic systems, when calculated based on the area actually grown with the main crops. In the O3 system some of the area of the vegetable fields was allocated to intercrops, so vegetable yields calculated based on total land area was only 63% of conventional yields. Differences in quality parameters of the harvested crops, i.e. nutrient content, dry matter content or damages by pests or diseases were few and not systematic, whereas clear effects on nutrient balances and nitrogen leaching indicators were found. Root growth of all crops was studied in the C and O2 system, but only few effects of cropping system on root growth was observed. However, the addition of green manures to the systems almost doubled the average soil exploration by active root systems during the rotation from only 21% in C to 38% in O2 when measured to 2.4m depth. This relates well to the observed differences in subsoil inorganic N content (N-inorg. 1-2 m depth) across the whole rotation (74 and 61 kg N ha(-1) in C and O1 vs. only 22 and 21 kg N ha(-1) in O2 and O3), indicating a strongly reduced N leaching loss in the two systems based on fertility building crops (green manures and catch crops). In short, the main distinctions were not observed between organic and conventional systems (i.e. C vs. O1, O2 and O3). but between systems based mainly on nutrient import vs. systems based mainly on fertility building crops (C and O1 vs. O2 and O3). (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Kumar, V.
    • Ahalawat, I. P. S.
    • Kumar, U.
    • Vivek
  • Source: Advances in Plant Sciences
  • Volume: 25
  • Issue: 1
  • Year: 2012
  • Summary: A field experiment was conducted at Agricultural Research Farm, J.V. College Baraut, Baghpat (UP), during two consecutive seasons of Rabi, 2001-02 and 2002-03 to find out the yield potential as influenced by different row ratios (4:1 and 6:1) in lentil+mustard intercropping, Levels of irrigations (control, 0.2 and 0.4 IW/CPE) and doses of fertilizers (30 Kg N+40 Kg P 2O 5/ha and 60 Kg N+60 Kg P 2O 5/ha) were applied in the present study. Association of lentil with mustard under 4:1 row ratio was found more suitable as it accounted for higher value in terms of land equitant ratio (LER) and yield potential. Irrigation @ 0.4 IW/CPE resulted maximum seed yield in lentil (9.90 q/ha.) and mustard (13.30 q/ha), to achieve higher yield advantage and efficient source utilization, Seed yield of both the crops was significantly increased with increasing levels of fertilizers up to 60 KgN+60 Kg P 2O 5/ha.
  • Authors:
    • Zheng, Y. K.
    • Yang, G. A.
    • Vasseur, L.
    • You, M. S.
    • Yao, F. L.
  • Source: Crop Protection
  • Volume: 34
  • Year: 2012
  • Summary: The frequent outbreaks of rice planthoppers, especially brown planthopper Nilaparvata lugens (Stal), in the last ten years in China and other Asian countries have caused serious rice ( Oryza sativa L.) yield losses. The key problem is possibly due to biodiversity loss in rice ecosystems. We examined the potential of intercrops of soybean ( Glycine max L.) and corn ( Zea mays L.), both of which are more profitable than rice and mostly planted in levees, to diversify rice ecosystems and enhance insect pest management. We studied the impacts of such intercrops on planthopper populations and their natural enemies. The results showed significantly lower numbers of rice planthoppers in rice fields with intercrops of corn than in rice monocultures and rice fields with intercrops of soybean. Rice fields with corn intercrops had 26-48% fewer planthoppers than rice monoculture. Rice fields with soybean intercrops had lower rice planthopper abundance compared to rice monoculture in 2008 but higher in 2009. However, neither parasitoid nor predator numbers were significantly affected by intercropping. There were no significant differences in directional movements of planthoppers or natural enemies between crop subplots in the different cropping systems. Moreover, movement of planthoppers was very limited. Our study indicated that soybean and corn intercrops do not greatly enhance the ability of natural enemies to suppress planthoppers. However, rice fields with intercrops of corn had lower abundance of planthoppers and this strategy may be useful as part of an integrated pest management strategy for the sustainable rice production.