• Authors:
    • Sanja, V.
    • Branko, M.
    • Aleksandar, M.
    • Dura, K.
    • Nenad, D.
  • Source: African Journal of Biotechnology
  • Volume: 11
  • Issue: 30
  • Year: 2012
  • Summary: The winter-sowing genotypes of common vetch ( Vicia sativa L.) are very susceptible to lodging and therefore are sown in mixtures with small grains that serve as supporting crops. In order to determine an optimum ratio of vetch and wheat ( Triticum aestivum L.) components in their mixture, a four-year trial (autumn 2005 to spring 2009) was carried out, aiming at the yield and quality of winter vetch haylage. The sowing rate of winter vetch was 120 kg ha -1, while the sowing rate of winter wheat was 0, 15, 20, 25 and 30 kg ha -1. An increased proportion of the cereal in its mixture with vetch significantly decreased the stand lodging, have a positive influence on forage yield, but haylage quality is of a poorer quality. Quality characteristics such as crude protein and lignin content, total digestible nutrients, dry matter intake and relative feed value were highest in monoculture common vetch followed by mixture with the lowest rate of wheat. Neutral detergent fiber content was positively affected by intercropping. There were no significant differences among treatments for acid detergent fiber content, digestible dry matter and net energy for lactation. The most favorable balance between the haylage yield and quality, as well as the highest crude protein yield (1482 kg ha -1), was achieved with the mixture of 120 kg ha -1 of the vetch seed and 15 kg ha -1 of wheat.
  • Authors:
    • Pannacci, E.
    • Onofri, A.
    • Graziani, F.
    • Tei, F.
    • Guiducci, M.
  • Source: European Journal of Agronomy
  • Volume: 39
  • Year: 2012
  • Summary: Long-term effects of organic (ORG) and conventional low-input (CONV) farming systems on size and composition of weed seedbank were assessed in 2007 in central Italy, in an on-farm experiment set up in 1996. In this experiment, six rotations (R1-R6) were considered, basically consisting on the same crop sequence with different starting points, i.e. (1) legume crop (soybean/field bean/common pea), (2) vegetable crop (pepper/melon), (3) winter cereal (soft/durum wheat), (4) summer cereal (maize) (5) industrial vegetable (processing tomato), (6) winter cereal (soft/durum wheat). All rotations were established both in ORG and in CONV, in strict adherence to EU regulations (ORG: EU reg. 2092/91; CONV: EU reg. 2078/92). Intercrops with green manuring purposes were included in ORG, while weed control was performed mechanically in ORG and chemically/mechanically in CONV. Weed seedbank was determined on 10 soil samples (0-0.30 m depth) in each plot and seeds were directly extracted, identified and counted. In all rotations, the adoption of ORG resulted in a significant increase in weed seedbank density, particularly in the case of summer weed species ( Portulaca oleracea L., Amaranthus retroflexus L. and Chenopodium album L.), which are more competitive and difficult to control in summer crops under organic farming systems in the Mediterranean climates. Small differences between ORG and CONV were found in terms of number of weed species (23 in ORG and 20 in CONV, on average), but the index of diversity in CONV was on average higher than in ORG. Furthermore, the most dominant weeds in CONV represented a lower percentage of total seedbank (40%, 23% and 5%, respectively, for P. oleracea, A. retroflexus and C. album in CONV and 56%, 32% and 4% for the same three weeds in ORG). These results confirm that the wider availability of effective weed control methods in integrated low-input farming systems (CONV) is helpful to maintain a low seedbank size, with a lower dominance structure. However, the adoption of ORG systems based on long rotation cycles, very competitive crops and accurate weed control, especially at the beginning of the ORG management, may be sustainable in the long run, in terms of potential weed infestation levels.
  • Authors:
    • O'Donovan, J.
    • Harker, K.
    • Clayton, G.
    • Dosdall, L.
    • Hummel, J.
  • Source: Environmental Entomology
  • Volume: 41
  • Issue: 1
  • Year: 2012
  • Summary: Diversity and abundance of ground beetles (Coleoptera: Carabidae) can be enhanced in vegetable and field intercropping systems, but the complexity of polycultures precludes the application of generalized assumptions of effects for novel intercropping combinations. In a field experiment conducted at Lacombe and Ellerslie, Alberta, Canada, in 2005 and 2006, we investigated the effects of intercropping canola ( Brassica napus L.) with wheat ( Triticum aestivum L.) on the diversity and community structure of carabid beetles, and on the activity density responses of individual carabid species. Shannon-Wiener diversity index scores and species evenness increased significantly as the proportion of wheat comprising total crop plant populations increased in one site-year of the study, indicating a positive response to enhanced crop plant species evenness in the intercrops, and in that same site-year, ground beetle communities in intercrops shifted to more closely approximate those in wheat monocultures as the percentage of wheat in the intercrops increased. Individual carabid species activity densities showed differing responses to intercropping, although activity densities of some potential root maggot ( Delia spp.) (Diptera: Anthomyiidae) predators were greater in intercrops with high proportions of wheat than in canola monocultures. The activity density of Pterostichus melanarius (Illiger), the most abundant species collected, tended to be greater in canola monocultures than high-wheat intercrops or wheat monocultures. We conclude that intercrops of canola and wheat have the potential to enhance populations of some carabid species, therefore possibly exerting increased pressure on some canola insect pests.
  • Authors:
    • Jamshidi, K.
  • Source: Desert
  • Volume: 16
  • Issue: 2
  • Year: 2012
  • Summary: In order to evaluate the yield, yield components and protein contents of two wheat cultivars (Zarrin and Gaspard) in sole cropping and intercropping systems,an experiment was conducted using replacement serious technique and different combinations of intercropping with high plant density and optimal of each cultivar. A factorial experiment was conducted in the form of randomized complete block design (RCBD) with three replications at the research farm of Agriculture Faculty of University of Zanjan at 2008-2009. The results showed that planting patterns has significant effect (alpha=0.01) on grain yield, the average number of grain per spike and protein content of each cultivar. The effect of plant density levels on grain yield of Zarrin cultivar was significant (alpha=0.01). The results indicated that the highest grain yield (9611 kg ha -1) was obtained from 2:2 ratios of (50% Zarrin+50% Gaspard) cultivars in plant density of 400 seed per m 2 which had Land Equivalent Ratio (LER) above 1.79. Land equivalent Ratio Index(LER) calculation showed that all intercrops had advantage compare to sole cropping system.
  • Authors:
    • Khan, M.
    • Said, G.
    • Khan, M.
    • Khan, S.
    • Inayat, U.
    • Khalid, U.
  • Source: Journal of Integrative Agriculture
  • Volume: 11
  • Issue: 6
  • Year: 2012
  • Summary: Conservational tillage (CT) in combination with broad spectrum herbicide may be more efficient and economical in controlling weeds, reducing cost of cultivation, and enhancing wheat yield. Field experiments were carried out to evaluate the effect of tillage and herbicides on weeds and wheat yield under rice-wheat cropping system (RWCS). The results indicated that broad spectrum herbicides particularly, carfentrazone ethyl ester+isoproturon (Affinity 50 WDG) reduced weeds density by 93 and 95% compared to control and also produced the maximum grain yield (6818 and 6996 kg ha -1) and HI (harvest index, 44.7 and 44.6%) in 2007-2008 and 2008-2009 growing seasons, respectively. The maximum weeds infestation and the lowest yield were recorded in control. Tillage methods significantly influenced grain yield and HI, while no significant effect on all other parameters. The overall mean yield was significantly higher in zero tillage (5575 kg ha -1) and reduced tillage (5584 kg ha -1) compared to CT (5479 kg ha -1). Besides increasing wheat yield, Affinity 50 WDG and zero tillage are important weed management practices that can be integrated into wheat production in RWCS. However, in case of perennial weeds or insect pests' infestation, CT in combination with Affinity 50 WDG would be more productive than conservation tillage.
  • Authors:
    • Rengel, Z.
    • Li, L.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 43
  • Issue: 13
  • Year: 2012
  • Summary: A pot experiment was conducted to determine the effects of chickpea/wheat intercropping and two phosphorus (P) sources on soil acidification and to explore a new way of ameliorating soil acidification. Wheat and chickpea roots were grown in compartments separated either by a solid barrier to prevent any root interactions or by a nylon mesh (30 m) to permit partial root interactions, or with no separation between the compartments. Two P sources were applied at 60 mg P kg -1 soil either as sodium phytate or ferrous phosphate (FePO 4). The decline of soil pH after growing plants for 42 days was alleviated by supplying organic P or intercropping while receiving organic P. The ameliorating of soil acidification resulted mainly from a decrease in excess cations over anion uptake of both wheat and chickpea under phytate supply, compared to FePO 4 supply. The excess cation uptake of chickpea was reduced by root interactions.
  • Authors:
    • Liu, We.
    • Meng, P.
    • Zhang, J.
    • Lu, S.
  • Source: Journal of Food Agriculture & Environment
  • Volume: 10
  • Issue: 2 part 3
  • Year: 2012
  • Summary: Agroforestry systems have unique advantages over conventional agricultural land in the carbon (C) balance. In this study, soil respiration under a tree intercropping system, an orchard and an agricultural land in north China were quantified during the growing season of March-November 2010. In the tree intercropping system, eight-year-old walnut ( Juglans regia L.) was intercropped with an annual wheat ( Triticum aestivum L.) - mung bean ( Vigna radiata L.) rotation. In the orchard and cropland, the eight-year-old walnut and wheat-mung bean rotation were grown as a mono practice, respectively. During the study period, the overall soil respiration rate was 1.89, 1.63 and 2.05 mol m 2 s 1 for the walnut intercropping, walnut orchard and cropland systems, respectively. Thus, there was a reduction in soil respiration when the cropland was converted to walnut intercropping and walnut orchard in north China. The higher soil CO 2 emission in the cropland result from the higher soil organic carbon and soil temperature. The van't Hoff model described the soil respiration as a function of soil temperature in the walnut intercropping system with R 2>0.78. Moreover, the temperature sensitivity of soil respiration (Q 10) was determined in the walnut intercropping system. The Q 10 values were similar in the walnut intercropping system and walnut orchard at 2.33 and 2.28, respectively, and significantly greater than for cropland (1.59). The result suggests that the walnut intercropping system had a higher sensitivity of soil respiration to temperature change than agricultural land. Compared with cropland, the slightly lower soil organic carbon in the walnut intercropping system may due to the short-term agroforestry practice, while in general the soil organic matter requires long term of turnover interactions. There was no significant difference in the walnut basal diameter and tree height between orchard and intercropping systems, showing that walnut growth was not affected by the introduction of the crop. Our results suggest that walnut intercropping could be practiced above conventional agriculture and produced less soil CO 2 emissions.
  • Authors:
    • Xu, L.
    • Li, W.
    • Ning, W.
    • Qiu, C.
    • Liao, K.
    • Ma, Y.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 49
  • Issue: 1
  • Year: 2012
  • Summary: Objective: In order to know the environmental temperature and humidity daily variation regularity in apricot-wheat intercropping zone. Method: Temperature and humidity recorder (EI-USB-2), and portable tester soil temperature and humidity (Stevens POGO) were used to detect the change of air temperature, land surface temperature and relative humidity in apricot-wheat intercropping zone and apricot monoculture zone were observed. Result: The results showed that, the temperature and humidity change lies both in intercropping zone and monoculture zone. There was a positive correlation between the temperature, land surface temperature and PAR, but a negative correlation between relative humidity and PAR. The average temperature and land surface temperature in intercropping zone decreased 4.53°C and 0.7°C, respectively; The average temperature and land surface relative humidity increased 4.90% and 3.93% respectively in intercropping zone. Conclusion: To some extent, intercropping has a significant function of reducing temperature decrease and humidity in the orchard.
  • Authors:
    • Ercoli, L.
    • Masoni, A.
    • Mariotti, M.
    • Arduini, I.
  • Source: Grass and Forage Science
  • Volume: 67
  • Issue: 2
  • Year: 2012
  • Summary: Intercropping (IC) cereals and legumes could be an option for obtaining forage suitable for ensiling and enabling reduced N fertilization. Two experiments were performed in central Italy with durum wheat ( Triticum durum Desf.) and field bean ( Vicia faba L. var. minor) grown for forage production in IC and as sole crops (SC) with different N rates (20 and 50 kg ha -1) and row ratios (1:1 and 2:1 cereal/legume). The aims were to assess (i) whether IC is a feasible option to reduce N fertilization; (ii) the best combination of practices to obtain forage suitable for ensiling; and (iii) competition/facilitation effects exerted by field bean on durum wheat. Results showed IC allowed fertilizer-N reduction and led to improved forage yield with better quality, compared with SC. Land equivalent ratio indicated a high efficiency of the IC, by up to 26% with respect to SC. Field bean was the dominant species of IC, but N fertilization reduced its competitive ability and enhanced that of wheat. In the intercrop fertilized with 50 kg N ha -1, the proportion of the wheat in the herbage (0.34-0.41 of the total dry matter) was sufficient for ensiling of the forage mass. Field bean exerted both competition and facilitation effects on the cereal. N uptake of durum wheat was greater under IC with beans than as wheat SC.
  • Authors:
    • Rodrigues, J. G. L.
    • Fernandes, D. M.
    • Bicudo, S. J.
    • Nascimento, F. M.
    • Fernandes, J. C.
    • Furtado, M. B.
  • Source: Revista Brasileira de Ciencias Agrarias
  • Volume: 7
  • Issue: 1
  • Year: 2012
  • Summary: The main goal of this research was to evaluate the response of maize crop in succession to maize+oat crops, with the anticipation of the increasing doses of nitrogen application in the oat culture, in no-tillage system. The experiment was carried out under field conditions at FCA/UNESP, Botucatu Campus, Sao Paulo, Brazil. The experimental design was arranged in randomized blocks with four replications, in split-plots. The plots were the nitrogen doses applied on the oat crop (0, 20, 40 e 60 kg ha -1), and split-plots, the nitrogen doses applied in the cover (60, 80, 100 e 120 kg ha -1), divided into two different crop stages of the maize crop. The dry matter weight and the C/N ratio were assessed on the oat and maize crops. On the maize crop, the plant nitrogen was quantified before the first covering and 15 days after the second covering, when the dry matter weight of the maize plants was determined. After the harvest, the yield was also calculated. Results indicate that the maize development and yield under no-till system were related to the straw C/N ratio, and the maize crop response to the anticipated N fertilization anticipation varied according to the N doses and application periods. The dry matter weight of the maize plants were influenced by the rates and periods of N applications.