• Authors:
    • Zavalin, A.
    • Pasynkova, E.
  • Source: Russian Agricultural Sciences
  • Volume: 36
  • Issue: 1
  • Year: 2010
  • Summary: It is shown that a comparative evaluation of the biological efficiency and intensity of competitive relations in cereal (spring wheat) and pulse (spring vetch) mixed crops is the most complete and accurate in yield of the main product (grain, dry matter) and biological yield (grain+straw+chaff, dry matter).
  • Authors:
    • Elliott, N.
    • Giles, K.
    • Phoofolo, M.
  • Source: Environmental Entolomology
  • Volume: 39
  • Issue: 3
  • Year: 2010
  • Summary: Creating conditions that enhance the abundance of resident populations of natural enemies in agroecosystems is considered critical to the efficiency of biological control of insect pests. We conducted a study to determine the potential of relay-intercropping for enhancing the abundance of aphidophagous lady beetles in sorghum. A relay-intercropping system consisting of alfalfa, winter wheat, and cotton as intercrops and sorghum as a main crop was compared with sorghum monoculture plots at two study sites in OK from 2003 to 2006. Lady beetles and aphids were sampled throughout the season using sticky traps and field counts on individual sorghum plants. Results from sticky traps and field counts show that differences in abundance and species composition of lady beetles between intercropped and monoculture sorghum were not statistically different during each year of study. Also, the lady beetle-greenbug ratios in relay-intercropped and monoculture plots were not significantly different. Lack of significant effects of relay-intercropping in our study may have been attributable to the confounding effects of spatial and temporal scale and the low number of aphids and other alternative prey in the intercrops compared with high incidence of corn leaf aphids in sorghum early in the season.
  • Authors:
    • Ponizil, A.
    • Henriksen, B.
    • Pozdisek, J.
    • Hunady, I.
    • Loes, A. K.
  • Source: Vyzkum v Chovu Skotu
  • Volume: 52
  • Issue: 3
  • Year: 2010
  • Summary: Controlled field trials with legume-cereal mixtures and monocultures were conducted on five organic farms in CR, to determine the suitability for feeding ruminants. Mixtures of 60% peas to 40% cereals (wheat and barley) were compared with peas, wheat, and barley monocultures. The obtained results are useful to assess how mixtures may be included in animal feed rations. For feeding beef cattle, it is most beneficial to harvest green matter in the BBCH 79 growth phase (green ripeness), which is characterized by a higher protein and energy content and a lower fiber content. Advantageous crop for beef cattle appeared to be the mixture with peas and barley, because the crude protein and NEL contents come the closest to the requirements for a balanced state between breakdown and synthesis in the rumen (CP 130 g kg -1, NEL 5.9 MJ kg -1 DM). The results support that legume-cereal intercropping is a feasible technology to produce high quality feed on organic farms, which may provide animals with good health, and potential to utilize their genetic capacity for growth and production.
  • Authors:
    • Chai, Q.
    • Qi, W.
  • Source: Chinese Journal of Eco-Agriculture
  • Volume: 18
  • Issue: 1
  • Year: 2010
  • Summary: A field experiment was conducted in China to investigate the effect of different root partition patterns on wheat/maize competitiveness under intercropping system and how it affects yield. Two root partition patterns (plastic film and nylon mesh partition patterns) were used. Results showed that wheat/maize competitiveness in intercropping system steadily increased from sowing to flowering stage of wheat and then decreased the competitive advantage of wheat over maize under intercropping decreases by root partitioning. Intercropping system without root partition increased the competitive advantage of wheat by 20.5 and 4.9% respectively, compared to those with plastic film and nylon mesh partitions. The land equivalent ratios of intercropping systems without root partition, with plastic film partition and nylon mesh partition were 1.46, 1.20 and 1.39, respectively. Yield for the intercropping system was quadratically correlated with wheat competitiveness to maize. Improving wheat/maize competitiveness in intercropping systems increased yield. The stage of wheat flowering was critical for optimizing wheat competitiveness.
  • Authors:
    • Li, S.
    • Zheng, Y.
    • Tang, L.
    • Qiao, P.
  • Source: Plant Nutrition and Fertilizer Science
  • Volume: 16
  • Issue: 5
  • Year: 2010
  • Summary: Crop varieties are different in nutrient uptake, and intercropping may influence nutrient uptake and disease incidence of the crops. Pot experiments were carried out to investigate the characteristics of N, P and K uptake and powdery mildew incidence of 6 wheat cultivars, which differed in powdery mildew resistance and were intercropped with faba bean: 2 highly resistant cultivars YM47 and YM53, 2 medium resistant cultivars YM42 and YM51 and 2 sensitive cultivars YX11-12 and YX93-124. The biomass of YM47 and YM53 increased by 11.9% and 6.6% in intercropping, compared with that in mono-cropping. Nitrogen contents of the leaves of intercropped wheat cultivars YM47 and YM53 and YX11-12 significantly increased, by 1.20-1.25 times in comparison with those of mono-cropping. The phosphorus contents of wheat leaves increased at the milky and ripening stages, and potassium content of wheat leaves significantly increased by 9.1-22.3% at the jointing stage under the intercropping. The incidence of wheat powdery mildew of all wheat cultivars significantly decreased under the intercropping system, the relative disease controlling effects being 0.76-81.49%. The most desirable disease-controlling effects under the intercropping were observed in YM42, YM53 and YM93-142 at the milky stage.
  • Authors:
    • Biradar, D. P.
    • Rathod, P. S.
    • Patil, V. C.
  • Source: Journal of Medicinal and Aromatic Plant Sciences
  • Volume: 32
  • Issue: 4
  • Year: 2010
  • Summary: A field experiment was conducted at Regional Agricultural Research Station, Bijapur on medium deep black soil during rabi seasons of 2004 and 2005 to study the influence of different rabi intercrops on growth and productivity of senna. The treatment consists of five rabi crops (chickpea, safflower, linseed, mustard and wheat) and senna in sole stand as well as intercropping system and safflower+chickpea (2:4) intercropping system as a check. The sole crop of senna recorded significantly better growth and growth parameters as compared to intercropped senna. The leaf and pod yield of senna also followed the same trend as that of growth and growth parameters with different rabi intercrops. Growing of senna with safflower adversely reduced the growth and growth parameters, leaf and pod yield as compared to chickpea, linseed, mustard and wheat.
  • Authors:
    • Carbonell, R.
    • Rodriguez-Lizana, A.
    • Gonzalez, P.
    • Ordonez, R.
  • Source: NUTRIENT CYCLING IN AGROECOSYSTEMS
  • Volume: 87
  • Issue: 2
  • Year: 2010
  • Summary: A common agricultural policy rule has banned the burning of wheat stubble. It might gradually increase the surface under no-till in Europe. The release dynamics of nutrients from the crop residues left on the soil surface has rarely been studied under Mediterranean climate conditions. As part of a long-term experiment started in 1982, a field study was carried out during the agricultural seasons 2001/2, 2002/3 and 2003/4, to determine the decomposition and nutrient release of above-ground residues deposited on a clayey soil in the south of Spain, in which a legume-cereal-sunflower rotation was followed. At the end of its decomposition cycle, the pea residue ( Pisum sativum L. cv. Ideal) had lost 60% of its initial mass, durum wheat ( Triticum durum L. cv. Amilcar) 35%, and sunflower ( Helianthus annus L. cv. Sanbro) 39%. The N release by the pea residue, wheat and sunflower was of 13.5, 6.7 and 8.5 kg ha -1, respectively. The P release was of 2.9 kg ha -1 (pea) and of 0.7 kg ha -1 (sunflower), and the highest content of released K was noted in the sunflower residue, 78 kg ha -1, compared to 22.5 kg ha -1 in wheat and 2.4 kg ha -1 in pea. In pea and sunflower, residue loss and N and P release in most cases followed simple linear and exponential functions, from which the specific decay rates were calculated. The decomposition rates of the different nutrients were higher than those of the residue in pea and sunflower, and the residue semi-decomposition periods, of 138 d in sunflower, and 191 d in pea, indicated a great persistence of the remains. The soil protection was acceptable in the case of wheat and sunflower, but not in pea. The application of the Douglas-Rickman model and the knowledge of the variation in the concentration of the nutrient in the crop remains permitted the estimation of the amount of N and P remaining in them over the intercropping period. In any case, in our climate and with soils rich in K, the release of nutrients from the residue, mainly N, is fairly scant and, in principle, does not seem to be of any interest in the fertilization programmes followed by the farmers in the area.
  • Authors:
    • Kadziuliene, Z.
    • Deveikyte, I.
    • Sarunaite, L.
  • Source: ZEMDIRBYSTE-AGRICULTURE
  • Volume: 97
  • Issue: 3
  • Year: 2010
  • Summary: The aim of the three-year study was to determine the impact of intercropping spring wheat with grain legumes on yield performance and stability, nitrogen use, weed control and grain quality. The experiment was carried out during 2007-2009 on a loamy Endocalcari-Epihypogleyic Cambisol ( CMg-p-w-can) in Dotnuva (55degrees24′N). Grain legumes: field pea ( Pisum sativum L.), lupin ( Lupinus angustifolius L.), bean ( Vicia faba L.), vetch ( Vicia sativa L.) and spring wheat ( Triticum aestivum L.) were sown as intercrops and sole crops and were grown organically for grain. The productivity of spring wheat sole crop or intercrops depended on the species of grain legume, however, the results varied over the experimental years. In 2007, the vetch and wheat intercrop produced a significantly higher grain yield than wheat in sole crop or in the other intercrops. In 2008, no advantages of legume and wheat intercrops were revealed. In 2009, the yield of sole legume crops was lower compared with the total wheat and legume intercrops. The concentration of crude protein was higher in grain yield, when spring wheat had been grown in intercrops. Vetch exhibited the best suppressing ability on weeds compared to all other grain legumes investigated. The total weed mass in spring wheat intercrops with grain legume was lower compared to that in the sole crops.
  • Authors:
    • Dube, R.
    • Dhyani, S.
    • Ratan, S.
    • Sharma, A.
  • Source: Indian Journal of Agronomy
  • Volume: 55
  • Issue: 4
  • Year: 2010
  • Summary: A field experiment was conducted at Selakui, Dehradun from 2001 to 2004 to study the effect of tillage, viz. conventional tillage (CT) and minimum tillage (MT); and weed-control practices, viz. chemical and mechanical weeding along with legume mulching, viz. in situ grown sunnhemp ( Crotalaria juncea L) and subabul [ Leucaena leucocephala (Lam.) de Wit] on soil moisture conservation, crop productivity and soil health in maize ( Zea mays L)-wheat ( Triticum aestivum L. emend Fiori & Paol.) cropping system. CT gave higher grain yield of maize (+0.11 to 0.17 t/ha), but wheat performed equally well under CT (2.48 t/ha) and MT conditions (2.36 t/ha). Chemical weeding with herbicides (alachlor in maize and isoproturon in wheat) resulted in 7.8 and 9.9% higher yield of maize and wheat, respectively over mechanical weeding. Beneficial effect of live mulching with sunnhemp or Leucaena was similar (12.3-14.7%), while their combined application increased the maize yield by 19.1% over no mulching. Further, enhanced soil moisture conservation due to mulching at maize harvest led to greater productivity of wheat by 16.1% with sunnhemp or Leucaena, and 27.0% with sunnhemp+ Leucaena. Nitrogen uptake of maize and wheat increased significantly with chemical weeding and legume mulching, but tillage practices made no effect on wheat while in maize it was lower under MT. Wheat gave 4-5 times more net returns than maize, and the net B:C ratio of the system was >1.0 with chemical weeding and legume mulching. Tillage and weed-control practices made no effect on organic C and total N status of soil but legume mulching improved these parameters and reduced bulk density associated with increased infiltration rate. It was concluded that CT along with legume mulching in maize and MT in wheat, and chemical weeding of both the crops was beneficial for improving moisture and nutrient conservation, and achieving higher productivity and profitability of maize-wheat cropping system under Doon valley conditions.
  • Authors:
    • Dube, R.
    • Dhyani, S.
    • Singh, R.
    • Sharma, A.
  • Source: NUTRIENT CYCLING IN AGROECOSYSTEMS
  • Volume: 87
  • Issue: 2
  • Year: 2010
  • Summary: Mulching with vegetative materials is a highly beneficial and widely-investigated agro-technique in rainfed areas but the adoption of this practice has been constrained due to non-availability of mulch biomass locally. Live mulching with fast-growing annual green manure legumes like sunnhemp ( Crotalaria juncea) or prunings of Leucaena leucocephala grown as hedge rows can be done for moisture conservation as well as nutrient cycling in the maize-wheat cropping system, which is predominantly followed in the high rainfall sub-mountainous region of north-western India. A field experiment was conducted at Selakui, Dehradun during 2000-2004 to study the effect of legume mulching, viz. in situ grown sunnhemp and Leucaena prunings, along with varying N levels, viz. 0, 30, 60 and 90 kg N ha -1 (to maize), and 0, 40 and 80 kg N ha -1 (to wheat) on productivity, soil moisture conservation and soil physico-chemical properties. Intercropped sunnhemp added 0.75-1.45 t dry matter and 21.6-41.3 kg N ha -1 at 30-35 days, while Leucaena twigs added 1.89-4.15 t dry matter and 75.2-161.3 kg N ha -1 at 60-65 days of maize growth. Live mulching with sunnhemp or Leucaena biomass improved soil moisture content at maize harvest (+1.15-1.57%) and crop productivity by 6.8-8.8% over no mulching. Combined use of both the mulching materials was more effective in improving the soil moisture content (+2.08-2.29%) and grain yield (15.1%) over their single application. Response of maize to N fertilizer application was significant up to 90 kg N ha -1, and it was relatively more pronounced under the mulching treatments. Residual effect of mulching on wheat showed an increase in yield of 10.2% with sunnhemp or Leucaena, and 27.9% with sunnhemp+ Leucaena. There was an improvement in organic C and total N status of soil, and a decrease in bulk density associated with an increase in infiltration rate due to mulching at the end of 4 cropping cycles. It was concluded that legume mulching is a highly beneficial practice for enhanced moisture and nutrient conservation, leading to increased productivity and soil health of maize-wheat cropping system under Doon valley conditions of north-western India.