- Authors:
- Urquiaga, S.
- Alves, B. J. R.
- Giacomini, S. J.
- Aita, C.
- Denardin, J. E.
- Dos Santos, H. P.
- Dieckow, J.
- Mielniczuk, J.
- Bayer, C.
- Zanatta, J. A.
- Conceição, P. C.
- Jantalia, C. P.
- Boddey, R. M.
- Source: Global Change Biology
- Volume: 16
- Issue: 2
- Year: 2010
- Summary: Conservation agriculture can provide a low-cost competitive option to mitigate global warming with reduction or elimination of soil tillage and increase soil organic carbon (SOC). Most studies have evaluated the impact of zero till (ZT) only on surface soil layers (down to 30 cm), and few studies have been performed on the potential for C accumulation in deeper layers (0-100 cm) of tropical and subtropical soils. In order to determine whether the change from conventional tillage (CT) to ZT has induced a net gain in SOC, three long-term experiments (15-26 years) on free-draining Ferralsols in the subtropical region of South Brazil were sampled and the SOC stocks to 30 and 100 cm calculated on an equivalent soil mass basis. In rotations containing intercropped or cover-crop legumes, there were significant accumulations of SOC in ZT soils varying from 5 to 8 Mg ha-1 in comparison with CT management, equivalent to annual soil C accumulation rates of between 0.04 and 0.88 Mg ha-1. However, the potential for soil C accumulation was considerably increased (varying from 0.48 to 1.53 Mg ha-1 yr-1) when considering the soil profile down to 100 cm depth. On average the estimate of soil C accumulation to 100 cm depth was 59% greater than that for soil C accumulated to 30 cm. These findings suggest that increasing sampling depth from 30 cm (as presently recommended by the IPCC) to 100 cm, may increase substantially the estimates of potential CO2 mitigation induced by the change from CT to ZT on the free-draining Ferralsols of the tropics and subtropics. It was evident that that legumes which contributed a net input of biologically fixed N played an important role in promoting soil C accumulation in these soils under ZT, perhaps due to a slow-release of N from decaying surface residues/roots which favored maize root growth.
- Authors:
- Wang, L.
- Chen, Z.
- Chen, X.
- Wan, Y.
- Yang, W.
- Gong, W.
- Yan, Y.
- Source: PLANT PRODUCTION SCIENCE
- Volume: 13
- Issue: 4
- Year: 2010
- Summary: The relay strip intercropping system of wheat-corn-soybean is widely used in southwest China. However, it is hard to obtain a stable production of soybean with this system, since soybean plants grow under shading by corn; the stems are thinner and susceptible to lodging. We examined the effects of seed treatment with uniconazole powder (0, 2, 4 and 8 mg kg -1 seed) on the growth of soybean seedlings under relay strip intercropping, some morphological characteristics and yield. The seedling height, first internode length, cotyledonary node height and leaf area per plant were decreased, while the stem diameter, root dry weight, shoot dry weight, root volume, leaf greenness and root to shoot dry weight ratio were increased by uniconazole treatment. The root vigor and root active absorption area were also increased significantly by uniconazole treatment. Moreover, 2 and 4 mg kg -1 uniconazole powder treatment increased shoot dry weight, number of pods per plant, number of seeds per pod and seed yield significantly. Thus, the results suggested that seed treatment with uniconazole powder at a suitable concentration can improve soybean seedling growth, resist the lodging and also increase the seed yield under shading by corn in relay strip intercropping system.
- Authors:
- Huang, G.
- Chai, Q.
- Yang, C.
- Source: Zhongguo Shengtai Nongye Xuebao / Chinese Journal of Eco-Agriculture
- Volume: 18
- Issue: 4
- Year: 2010
- Summary: A field experiment was carried out to investigate the effect of alternative irrigation on water consumption, yield and water use efficiency ( WUE) under wheat-maize intercropping in the oasis region of Shiyang River Basin, Gansu Province. The results indicate that evaporation for alternative irrigated intercropping system (AI) decreases by 44.0 mm compared to conventional irrigated intercropping system (CI). Water consumption under AI also increases by 15.4 mm while yield and WUE are respectively enhanced by 13.92% and 9.21% compared to CI. All these results show that alternative irrigation is an effective and practicable way to improve yield and WUE of wheat-maize intercropping. Although evaporation and water consumption in alternative irrigated intercropping system increase with increasing irrigation quota, overall WUE actually decreases.
- Authors:
- Yang,C. H.
- Chai,Q.
- Huang,G. B.
- Source: Plant Soil and Environment
- Volume: 56
- Issue: 6
- Year: 2010
- Summary: A field experiment was conducted to investigate the effects of alternate irrigation (AI) on root distribution and yield of wheat ( Triticum aestivum L.)/maize ( Zea mays L.) intercropping system during the period of 2007-2009 in an oasis of arid north-west China. Five treatments, i.e. sole wheat with conventional irrigation (W), sole maize with alternate irrigation (AM), sole maize with conventional irrigation (CM), wheat/maize intercropping with alternate irrigation (AW/M), and wheat/maize intercropping with conventional irrigation (CW/M). The results showed that root growth was significantly enhanced by alternate irrigation (AI), root weight density (RWD), root length density (RLD) and root-shoot ratios (R/S) in AI treatments were all higher than those in conventional irrigation (CI) treatments. Moreover, intercropped wheat and maize also had a greater root development at a majority of soil depths than wheat and maize in monoculture. In three years, AW/M always achieved the highest total seed yield under different treatments. Higher yield and reduced irrigation resulted in higher water use efficiency (WUE) for the AW/M treatment. Our results suggest that AI should be a useful water-saving irrigation method on wheat/maize intercropping in arid oasis field where intercropping planting is decreased because of limited water resource.
- Authors:
- Source: Scientia Agricultura Sinica
- Volume: 43
- Issue: 1
- Year: 2010
- Summary: Objective: The aim of this study was to investigate the effects of weak light on the photosynthetic characteristics of peanut leaves at the seedling stage and to offer a theoretical basis for the programming of peanut intercropped with wheat. Method: Fenghua 1 was grown in an experiment with four shading treatments (CK, in which the plants were grown under natural light, and 27% shading, 43% shading, 77% shading) and the investigation was carried out at seedling stage using black sunshade net. The chlorophyll content, net photosynthetic rate, photosynthetic curve, fluorescence parameters and photosynthetic enzyme activities were tested. Result: Shading treatment significantly reduced the net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO 2 concentration (Ci), light compensation point, light saturation point, CO 2 compensation concentration, CO 2 saturation concentration, carboxylation efficiency, RUBPCase and PEPCase activities along with the shading degree but increased the chlorophyll content, apparent quantum yield, and Phi PS II and Fv/Fm. Real-time low light intensity and long-term shading treatment depressed photosynthetic enzyme activities jointly. Conclusion: Shading at seedling stage depressed Pn significantly, which induced by stomatal limitation and non-stomatal factors (such as decline of photosynthetic ability of mesophyll cell, changes of absorbed light allocation of PS II), improved the capacity of utilization of weak light. Shading of 27% had less influence, and therefore can program plant the standards of intercropping system of wheat and peanut.
- Authors:
- Dong, G.
- Chen, Z.
- Wu, Z.
- Sun, C.
- Chen, L.
- Zhang, Y.
- Source: Plant Soil and Environment
- Volume: 56
- Issue: 11
- Year: 2010
- Summary: Agricultural practices that reduce soil degradation and improve agriculture sustainability are important particularly for dry hilly land of Chaoyang County in the Liaoning Province, North-east China, where cinnamon soils are widely distributed and mainly for wheat production. The impacts of 10-year cropping systems (wheat-cabbage sequential cropping, wheat-corn intercrop, wheat-sunflower rotation, wheat-soybean rotation) on soil enzyme properties of surface-soil (0-20 cm) were studied. Total carbon, nitrogen, phosphorus and sulfur, and nine soil hydrolases related to nutrient availabilities (beta-galactosidase, alpha-galactosidase, beta-glucosidase, alpha-glucosidase, urease, protease, phosphomonoesterase, phosphodiesterase, arylsulphatase) and five enzymes kinetic characters were examined. Wheat-corn intercrop systems had higher total C, total N, total P and total S concentrations than wheat-soybean and wheat-sunflower rotation systems. Most test enzyme activities (alpha-galactosidase, beta-galactosidase, alpha-glucosidase, beta-glucosidase, urease, protease, phosphomonoesterase and arylsulphatase) showed the highest activities under wheat-corn intercropping system. Urease, protease and phosphodiesterase activities of wheat-cabbage sequential cropping system were significantly higher than two rotation systems. The maximum reaction rates of enzymes ( Vmax) were higher than apparent enzyme activity, which suggests larger potential activity of enzymes, while not all kinetic parameters were adaptive as soil quality indicators in dry hilly cinnamon soil.
- Authors:
- Source: World Journal of Agricultural Sciences
- Volume: 6
- Issue: 5
- Year: 2010
- Summary: It is becoming a necessity to intensify crop production in the face of the ever shrinking per capita agricultural land Experiences elsewhere suggest that intercropping potato with sorghum could be a feasible alternative so as to intensify production and give cash and food source alternatives for subsistence farmers. Three intercrop proportions (intercropping full density of potato with 75, 50 and 25% of sole crop density of sorghum) were compared with sole crops of potato and sorghum in a RCB of four replications for two years on sites representing sandy clay loam and clay black soil so as to determine compatible proportions of sorghum for intercropping with full density of potato. Marketable tuber yield of potato on sandy clay loam soil was not significantly affected by intercropping but it was significantly (P
- Authors:
- Rajat, P.
- Singh, N.
- Amitava, K.
- Source: Journal of Entomological Research (New Delhi)
- Volume: 34
- Issue: 2
- Year: 2010
- Summary: The field study on effect of intercropping on population dynamics of major insect pests and vectors of potato revealed that all the treatments viz., T 2=Potato+recommended pesticide schedule of the area, T 3=Potato+Onion in alternative rows (1:1), and T 4=Potato+Garlic in alternative rows (1:1) were statistically superior and significant over control (T 1). Potato along with recommended pesticide schedule was the most effective treatment in reducing the population of cutworm, various defoliators, epilachna beetle, aphid, whitefly and other pests as well as damage caused by the pests.
- Authors:
- Source: APANews
- Issue: 37
- Year: 2010
- Summary: The cultivation of vegetables under Dendrocalamus asper plantation in Jharkhand, India, is briefly described. The five-year old plantation was intercropped with potatoes, tomatoes, ginger and pea. The yield of potatoes, ginger and tomatoes decreased when cultivated in a bamboo plantation as compared to the data from the monoculture plantation. The performances of pea and ginger were found satisfactory.
- Authors:
- Afshar, A.
- Behrooz, M.
- Aynehband, A.
- Source: American-Eurasian Journal of Agricultural and Environmental Science
- Volume: 7
- Issue: 2
- Year: 2010
- Summary: Intercropping system of cereal with legume or some non-legume is a common practice in many developing countries because it may produce higher forage quantity and quality product than monocropping. The objective of this study was to evaluate the effects of mixture system and planting ratios on forage yield and yield components of two intercropping systems including maize:amaranth and maize:mung bean. This field study was conducted during 2008-09 under Mediterranean region in Ahvaz, Iran. The experimental design was split plot with three replications. Our results showed that both intercropping systems at the 75:25 mix-proportion had the highest intercropping dry matter yield. However, regardless of planting ratios, maize:amaranth had the highest intercropping dry matter. But, maize:mungbean at this condition was observed to be the most LER advantages. Furthermore, greater dry matter in maize:amaranth intercropping system mainly was due to higher leaf weight and stem weight values in this mixture than maize:mungbean systems. Means stem and leaf weights were higher in maize:amaranth than maize:mungbean mixture. However, yield of all maize intercropping systems were less that it was in monocropping. The ratio of proportion also seemed to had significantly affect on yield components of both intercropping systems and all crops. Despite of maize dry matter decrease in intercropping system as compared to sole stand, mixing of legume or some pseudocereal in cereal is a suitable alternative to increase the quality of cereal fodders.
