• Authors:
    • Shi, H.
    • Luo, Y.
    • Xue, J.
    • Wu, D.
  • Source: Journal of Nanjing Forestry University (Natural Sciences Edition)
  • Volume: 36
  • Issue: 2
  • Year: 2012
  • Summary: By using in situ leaching device, a field experiment was conducted to study the nitrate leaching amount and density at 60 cm soil depth, nitrate accumulation in soil profile (0-80 cm) of poplar-wheat intercropping ecosystem. Four treatments were installed, no fertilization (N 0, 0 kg/hm 2) conventional fertilization (N 140, 140 kg/hm 2), reduced N application (N 70, 70 kg/hm 2), increased N application (N 210, 210 kg/hm 2). The results indicated a positive correlation between quantity of leachate water and precipitation, the poplar-wheat intercropping ecosystem can reduce the quantity of eluviate solution. The nitrate leaching loss increased according to the increasing N fertilization rate. In treatment spot N 210, the nitrate nitrogen loss from N fertilization at 60 cm soil depth was the greatest (13.89 kg/hm 2), it declined by 60.27% and 50.11% in poplar-wheat intercropping ecosystem away from the poplar row 0.5 m and 1.5 m, respectively. The nitrogen leaching and accumulation were significantly lower in poplar-wheat intercropping ecosystem, and variances of the distribution for soil nitrate nitrogen were significant.
  • Authors:
    • Li, Y.
    • Liu, G.
    • Yang, L.
    • Ma, L.
    • Xia, L.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 28
  • Issue: 14
  • Year: 2012
  • Summary: Protective management of arable slope land plays an important role in protection of land resource and aquatic environment in Three Gorges region, China. Base on the regional natural conditions and the utilization of the arable slope land, four tillage modes with H1 (rotation of wheat and maize, wheat intercropped with horse bean, less tillage and ridge cultivation), H2 (rotation of wheat and maize, with Vetiveria ziz anioides contour hedges intercropped at slop length interval of 5 m), H3 (rotation of wheat and maize, with alfalfa contour hedges intercropped at slop length interval of 5 m), H4 (rotation of wheat and maize, conventional management) were conducted from Oct. 2009 to Oct. 2011. The differences of apparent recovery efficiency and Agronomic efficiency of applied nitrogen and phosphorus between treatments were discussed, as well as nitrogen and phosphorus losses through slope land surface runoff were analyzed. The results showed that compared with H4, H1 increased phosphorus use efficiency by 0.06 kg/kg. No significant difference of biological and economic production, apparent recovery efficiency and agronomic efficiency of applied nitrogen and phosphorus was observed among H2, H3 and H4, which showed intercropping with Vetiveria ziz anioides or alfalfa contour hedges wouldn't lead to the reduction of production. Furthermore significant effects on reducing soil erosion and sediment phosphorus loss were observed for H1, H2 and H3. Compared with H4, and sediment losses for H1, H2 and H3 decreased by 48.46%, 52.26% and 58.59% respectively, and sediment phosphorus losses decreased by 30.58%, 47.70% and 44.58% respectively.
  • Authors:
    • Francis, F.
    • Liu, Y.
    • Sun, J.
    • Zhou, H.
    • Cheng, D.
    • Chen, J.
    • Xie, H.
  • Source: Journal of Economic Entomology
  • Volume: 105
  • Issue: 3
  • Year: 2012
  • Summary: The effects of intercropping wheat, Triticum aestivum L., with mung bean, Vigna radiate L., on the populations of English grain aphid, Sitobion avenae (F.) (Hemiptera: Aphididae), and its natural enemies were evaluated by field and laboratory experiments. The population densities of aphids and their natural enemies were evaluated in the intercropped field against different row ratio combinations of wheat-mung bean. Results showed that wheat-mung bean intercropping caused a drop in aphid densities, and the ratio 12 wheat:4 mung bean brought about the largest drop (>18%). In addition, the population densities of coccinellids (ladybirds) and parasitoids and the species diversity of all the natural enemies of aphid were higher in the intercropped field than in the field planted only with wheat. However, intercropping did not influence the community indices (evenness and index of dominance concentration) of the natural enemies. Y-tube olfactometer bioassays were carried out in the laboratory to test whether odor blends of host and nonhost plants affect the host selection of S. avenae. Bioassays indicated that both apterous and alate aphids significantly preferred host plant odor over odor blends of host and intercropped species. Hence, the olfactory-based host location of aphids in the field might be affected by intercropping. The intercropping experiment clearly showed that increased crop species diversity suppresses aphid population growth and preserves the population of natural enemies of aphids. Our results also provide support for the "resource concentration hypothesis" and the "enemies hypothesis".
  • Authors:
    • Yahuza, I.
  • Source: International Journal of Biosciences (IJB)
  • Volume: 2
  • Issue: 6
  • Year: 2012
  • Summary: Five experiments agronomically managed differently investigated yield-density relationships in wheat/faba bean (bean) intercropping system. For the wheat sole crop, seed yield (SY) ranged from 102 g/m 2 to 734 g/m 2. Intercropping reduced wheat SY but this did not always depend on wheat seed rate (wsr). Standard intra-specific and/or inter-specific yield-density equations derived from the literature and others modified here were used to quantify the SYs (as was applicable). For the majority of the experiments wheat SYs, whether sole cropped or intercropped responded asymptotically as wsr increased. The maximum bean sole crop SY was 392 g/m 2: bean SY declined as wsr increased. The total intercrop (wheat+bean) SY response to wsr was asymptotic in at least two of the experiments, following similar pattern as the wheat. Although, for the mean effects of intercropping the total intercrop SYs was substantial in three experiments; the total intercrop did not produce significantly greater SY than the wheat sole crop as wsr increased. Moreover, maximum wheat sole crop and wheat intercrop SYs were significantly greater under the organically-managed experiment than the conventional-managed one, even though they were both established in the same cropping year. Similarly, as regards wheat SYs, comparisons of spring-sown with the winter-sown crops established in the same cropping year indicate that the former performed better than the latter. Nevertheless, for most of the experiments investigated here, this research indicates that 100-wheat seeds/m 2 or lower may be appropriate to intercrop with bean at 30 to 40-bean seeds/m 2 to reduce competition and improve productivity.
  • Authors:
    • Zhang, P.
    • Lu, C.
    • Xie, H.
    • Gong, P.
    • Yang, L.
    • Yang, B.
    • Xu, Y.
    • Zhang, W.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 49
  • Issue: 3
  • Year: 2012
  • Summary: Objective: The purpose of this project was to provide theoretical basis for the selection of suitable almond shape in almond-wheat intercropping systems through the research of four different almond tree cultivation shapes' canopy, photosynthetic rate and micro environment indicators, and the effect on lighting distribution and growth behaviors of intercropping wheat. Method: Ten years-old Wanfeng-almond trees were used as testing materials, and four structure treatments such as trunk-delaminating shape, open-center shape, spindle shape and high-stem round capitiform were set to study the difference among those four tree shapes and survey lighting distribution and wheat growth condition. Result: The load of per spindle shape tree was 1,184 per plants, which was lower than trunk-delaminating treatment. Due to small canopy volume of spindle shape, the load of unite projection plane was the highest, reaching 94.8 per m 2, and it was 2.06 times of trunk-delaminating treatment. The spindle shape tree's inner crown lighting distribution condition was better than other three treatments, reaching 31% of nature condition. Effect of spindle shape treatment on overshadow of intercropping area was lower, and stained lightly. The light intensity of overall intercropping area and at the both sides of the near crown areas was respectively 40.89% and 34.57% of nature condition. Conclusion: The preliminarily research showed that the spindle tree had high yield and lower influence on intercropping area, and it is suitable for the tridimensional composite planting system.