• Authors:
    • Tang, L.
    • Zheng, Y.
    • Ren, J.
    • Wang, Y.
  • Source: Journal of Yunnan Agricultural University
  • Volume: 26
  • Issue: 6
  • Year: 2011
  • Summary: Through field experiment, we studied the dynamics change of phosphorus in rhizosphere and bulk soil under wheat and faba bean intercropping and wheat monoculture, and the effects rhizosphere and bulk soil phosphorus under wheat and faba bean intercropping and wheat monoculture. The results showed that there was consistency in each growth date of rhizosphere soil phosphorus under wheat intercropping and monoculture, the bulk soil phosphorus content was highest in filling under wheat monoculture, and reached the highest in tilling under wheat intercropping. In wheat and faba bean intercropping, the rhizosphere soil phosphorus content of wheat was increasing from tilling stage to filling stage, and the rhizosphere and bulk soil phosphorus content in maturity was dramatically bringing down. The rhizosphere soil phosphorus contents of wheat increased by 6.81%, 8.71% and 12.95% in jointing, tilling and filling stages, respectively, and reduced by 21.11% in maturity stage.
  • Authors:
    • Yang, L.
    • Yin, S.
    • Xia, L.
    • Yu, Y.
    • Wu, D.
  • Source: PEDOSPHERE
  • Volume: 21
  • Issue: 6
  • Year: 2011
  • Summary: In the Three Gorges Area of China, soil erosion and the resultant non-point source pollution and ecological degradation have endangered agricultural ecosystems and fresh water reservoirs. Although efforts have been undertaken to reduce soil and water losses from slope land used for citrus production, information on the effects of management practices on soil fertility indices is either limited or nonexistent. This study was conducted to compare the effects of 10 years of various management practices, citrus intercropped with white clover (WC), citrus mulched with straw (SM), citrus intercropped with contour hedgerows (CH), citrus orchard land with impermeable membrane (IM), and citrus intercropped with wheat ( Triticum aestivum) and peanut ( Arachris hypogaea) (WP), as treatments on soil fertility indices with that of the conventional citrus management (CM). Results showed that the soil organic carbon, total and available nitrogen, available potassium, and water-stable aggregate (>0.25 mm) contents at the 0-5 cm depth were higher for the WC and SM treatments than the CM treatment. There was also spatial variation in soil fertility along slopes of the WC and SM treatments. The soil total and available nitrogen, phosphorus, and potassium, and water-stable aggregate (>0.25 mm) contents at both the 0-5 and 5-20 cm depths were higher for the CH and IM treatments than the CM treatment. The average soil available nitrogen and available potassium contents were higher for the WP treatment than the CM treatment, but the WP treatment had little effect on the soil organic carbon, total nitrogen, and water-stable aggregate (>0.25 mm) contents. These suggested that white clover intercropping and straw mulching were the most effective approaches to improve soil fertility in citrus orchard land of the Three Gorges area.
  • Authors:
    • Yahuza, I.
  • Source: International Journal of Biosciences (IJB)
  • Volume: 1
  • Issue: 5
  • Year: 2011
  • Summary: Intercropping (growing two or more crops together simultaneously) is increasing being adopted worldwide, probably because there have been suggestions that the system is beneficial in terms of land use efficiency compared to sole cropping. There are several indices for estimating intercrop performance compared to the component sole crops, but as reviewed in this paper, the land equivalent ratio (LER) is the most widely adopted. Yet the LER is constrained because it is not able to account for the relative duration each component in the intercrop spent in the field may have had on intercropping performance. Area time equivalency ratio (ATER) appears to have solved this problem well. However, neither ATER nor LER can account for the physiological or physical basis for the intercropping performance. The crop performance ratio (CPR) is more appropriate in this regard, even though CPR 'adjusted for time', (CPRT) is more efficient where the component crops differ in growth duration. In addition, particularly for intercrops with commercial value, there may be a need to compute a monetary advantage (MA) for intercropping. This paper concludes that in addition to the LER, for certain intercrops such as wheat/faba bean system that has not been widely adopted, there may be a need to use other indices such as ATER, CPR, CPRT and MA as may be applicable in order to understand more fully the nature of intercrop benefits that may exist. Indeed such type of information may help to attract potential growers.
  • Authors:
    • Xu, L.
    • Zhang, P.
    • Guo, W.
    • Liu, R.
    • Yang, C.
  • Source: Jiangsu Journal of Agricultural Sciences
  • Volume: 27
  • Issue: 5
  • Year: 2011
  • Summary: To investigate the effect of wheat-cotton double cropping system on cotton, planting pattern experiments in field were conducted in 2009-2010, with wheat-cotton intercropping system as control. The indexes of development characteristics and yield component of cotton were analyzed. The results were showed as follows. In wheat-cotton intercropping treatment, the development process was earlier, and the forming of fruit node and boll was longer and more than those of cotton transplanted after wheat harvest. The later autumn boll percent was only 3.2%-4.7% and the rate of blossom before frost was 88.6%-95.7%. The cotton in intercropping system also had high biomass and harmonious relationship between vegetative growth and reproduction. For cotton transplanted after wheat harvest treatments, the dry matters were low and pre-summer bolls were few. For cotton with substrate or nutrition treatment, the forming of fruit node and boll was later and less than those of cotton with intercropping treatment, the late autumn boll percents were 11.8%-20.8%, and the rate of blossom before frost was 77.2%-90.7%. The seed yield of cotton with substrate treatment was lower than that of cotton with intercropping treatment, but higher than that of cotton with nutrition treatment. For direct seeding cotton of medium-matured variety after wheat harvest, the reproductive growth was later and weaker. The forming of fruit node and boll was later and had no obvious peak, which easily caused invalid growth at later stage. The late autumn boll percent was 24.5%-34.0% and the rate of blossom before frost and seed yield were low. For direct seeding cotton of early-matured variety after wheat harvest, the transforming growth from vegetative to reproductive growth was earlier. The forming of fruit node and boll was concentrated with higher peak value and the total dry matter in reproductive organ was higher. The late autumn boll percent was only 3.3% and the rate of blossom before frost was 88.0%. The seed yield was equal to that of cotton transplanted after wheat harvest. As a result, the yield of cotton in intercropping system was higher and more stable, and that of transplanted cotton might be potential, while that of direct seedling cotton depended on the variety characteristics.
  • Authors:
    • Smith, D.
    • Yang, W.
    • Chen, X.
    • Liu, W.
    • Zhang, J.
  • Source: African Journal of Agricultural Research
  • Volume: 6
  • Issue: 27
  • Year: 2011
  • Summary: Production practice shows shaded soybean in wheat-maize-soybean; relay strip intercropping system has better tolerance to drought as compared with sole cropping soybean. Our researches are to understand the reasons through non-hydraulic root signals (nHRS), yield and the relationships among them. Pot experiments were conducted with two soybean cultivars, under shade of maize (LI) and normal irradiance (HI). nHRS were traced during manipulative progressive soil drying period at branching stage under good soil conditions (HW), water stress treatment (LW), in 2010. Well-watered (WW), light drought (LD), moderate drought (MD) and severe drought (SD) were applied in 2009. In response to soil drying, nHRS appeared earlier in Gongxuan No.1 (GX) than Gongqiudou 05-8 (GQ) under two irradiance treatments, but it disappeared earlier for GX than GQ under normal irradiance. GX exhibited a wider average soil water content threshold range (TR) of nHRS under low irradiance. Drought stress significantly decreased the shoot dry mass, root mass and grain yield (P
  • Authors:
    • Li, Z.
    • Zhang, M.
    • Sun, X.
    • Song, X.
    • Zhao, Q.
  • Source: Plant Nutrition and Fertilizer Science
  • Volume: 17
  • Issue: 6
  • Year: 2011
  • Summary: Soil microorganism quantities and enzyme activities were studied in fields under wheat-cotton and garlic-cotton intercropping systems. Compared with cotton monoculture, both intercropping systems proved to be conducive to the proliferation of soil bacteria and actinomycetales and inhibited proliferation of fungi, the effects of the garlic-cotton intercropping system being more pronounced than those of the wheat-cotton intercropping system. Throughout the growth period of the cotton crop, soil urease activity and sucrase activity in 0-20 cm soil layer in the garlic-cotton intercropping system were significantly higher than in cotton monoculture, and the alkaline phosphatase activity in the garlic-cotton intercropping system was significantly higher than that in the cotton monoculture except at the flowering and blooming stages of cotton. The catalase activities in the garlic-cotton intercropping system at the seedling stage and boll-opening stage were significantly higher than in cotton monoculture. In the wheat-cotton intercropping system, soil urease activity and sucrase activity in the 0-20 cm soil layer at the seedling, flowering and boll stages of cotton were higher than in cotton monoculture, alkaline phosphatase activity at the bud stage was significantly higher than in cotton monoculture, and catalase activity at the seedling and boll opening stages was significantly higher than in cotton monoculture. In conclusion, the garlic-cotton and the wheat-cotton intercropping systems can increase the quantities of soil bacteria and actinomycetales, thus effectively suppressing the occurrence of succession cropping obstacles in cotton fields, and they also increase the activities of soil-related enzymes, which is good for creating healthy soil in cotton fields.
  • Authors:
    • Abusuwar, A.
    • Omer, E.
  • Source: Agriculture and Biology Journal of North America
  • Volume: 2
  • Issue: 1
  • Year: 2011
  • Summary: A field experiment was carried out for two consecutive seasons (2005/2006 and 2006/2007) in the Demonstration Farm of the Faculty of Agriculture at Shambat, University of Khartoum, Sudan, to study the effect of intercropping, phosphorus application and Rhizobium inoculation on the performance of some leguminous and cereal forage crops. The treatments used were pure stand, a mixture of Clitoria, lablab and Sudangrass, phosphorus fertilizer and Rhizobium inoculation. They were laid out in a completely randomized block design with three replications. Yield and quality were measured. Land equivalent ratio (LER) was calculated to evaluate intercropping versus monocropping. The results of the field experiment showed that, sole crop yield was higher than when grown in a mixture. The mixtures especially legume/legume combinations, gave more total forage yield than the sole crops. Nearly all the intercropping treatments had land equivalent ratio (LER) above one which indicated the advantage of intercropping over monocropping. Rhizobium inoculation and phosphorus application improved forage quality by increasing crude protein content. Intercropping and phosphorus fertilization decreased crude fiber percentage in the plant tissues.
  • Authors:
    • Kahrizi, D.
    • Dehaghi, M.
    • Heidari, S.
    • Mofrad, A.
    • Azizi, K.
  • Source: African Journal of Biotechnology
  • Volume: 10
  • Issue: 1
  • Year: 2011
  • Summary: In order to investigate the effect of intercropping and sole cropping of barley and narbon vetch with weed control and interference conditions on their qualitative and quantitative traits, this experiment was conducted with 5 levels of intercropping (seed contribution): sole cropping of narbon vetch, 75:25 (narbon vetch : barley), 50:50, 25:75 and sole cropping of barley. Two levels of weed control and weed interference in row replacement series system in the form of factorial was designed with Randomized Complete Blocked Design (RCBD) in 3 replications in the College of Agriculture, Lorestan University, from 2006-2007. Results showed that the interaction of weed and the contribution of complementary components of intercropping has significant effect on crude protein (CP) and neutral detergent fibers (NDF) content in barley. Maximum CP and NDF were related to sole cropping of barley (infected by weeds), and maximum CP with minimum NDF were related to (narbon vetch: barley) 75:25 treatment, so that 31% of CP decreased in sole cropping of barley (infected by weeds) when compared with 75:25 combination. NDF percentage in sole cropping increased to 16.6%, therefore 25:75 (narbon vetch: barley) combination was better than the others. So, in order to get proper percentage of protein and digestibility of forage for livestock, 75:25 (infected by weeds) combination is better, especially the combination of 25:75 (infected by weeds), due to its high protein content. The highest and lowest dry forage production of barley were related to its sole cropping (a control which is equal to 3.75 t/ha) and 75:25 barley (infected by weeds that are equal to 1.59 t/ha), respectively.
  • Authors:
    • Castoldi, G.
    • Costa, L.
    • Steiner, F.
    • Costa, M.
    • Pivetta, L.
  • Source: Revista Ceres
  • Volume: 58
  • Issue: 2
  • Year: 2011
  • Summary: The use of animal manure combined with cover crops can provide sustainability to agricultural systems. Aiming to evaluate the effect of two farming systems and nutrient sources on the corn crop, an experiment was conducted on an Oxisol, in the municipality of Marechal Candido Rondon, Parana State, Brazil. The experiment was arranged in a randomized block design with treatments in a factorial scheme 2*3, consisting of two crop systems (succession wheat/corn and intercropping oat+vetch+turnip/corn) and three nutrient sources (mineral, organic and organic-mineral), with four replications. In June 2006, the wheat crop and the intercropping of cover crops were established. In October 2006, the corn was sowed on the two systems. Organic and organic-mineral fertilizations consisted of application of pig manure alone and combined with mineral fertilizer, respectively. Intercropping of oat, hairy vetch and wild radish produced adequate amount of biomass, showing its viability for providing soil cover during winter. Corn grown in rotation with wheat yielded the highest uptake of N and K and highest yield. Mineral fertilization gave higher N uptake and corn yield compared with the organic fertilizer and organic-mineral fertilizer based on pig manure.
  • Authors:
    • Darbandi, M.
    • Asadi, S.
    • Hokmalipour, S.
    • Sharifi, R.
    • Barmaki, M.
    • Darabad, G.
  • Source: World Applied Sciences Journal
  • Volume: 15
  • Issue: 2
  • Year: 2011
  • Summary: In order to study the phenology and competition of potato and safflower, as compared to those of the pure cropping, a study was carried out using factorial experiment with completely randomized block design, with three replications. This study was done in experiment field of University of Mohaghegh Ardabili in 2010. The investigated treatments included potato pure cropping in the fixed density of 6 plants pre m 2, safflower pure cropping with the densities of 6, 12 and 18 plants per m 2 and the intercropping of potato (6 plants pre m 2 density) with safflower in the densities of 6, 12 and 18 plants per m 2. The analysis of variance in phenology stages of pure culture and mixed with potatoes showed that all treatments were significant differences. Comparison mean the stages of phenology of safflower intercropping with potatoes showed that two stage emergence and stem elongation earlier seen in plant grown intercropping 18 plant in per. Mixed safflower plants and potatoes compared to other treatments. Delay was seen the phenology stages of flowering and handle the product because the longer vegetative phase and later getting into the reproductive stage, in terms of lime. Safflower competition mean the stage phenology of safflower effected density of potato showed that pure cultures of safflower compared with intercropping earlier spend of emergence, the stem elongation and head visible, flowering and seed ripening. Coefficient of relative congestion in all treatments on potatoes is greater than one, this study shows advantage competitive potatoes compared to safflower. Similarly, the smaller of these indexes suggest weak competition in safflower as compared to potatoes. Amount of relative yield total of potatoes and safflower in all treatments intercropping was smaller than the one. It shows that both components mixed to compete for use limited recourses.