• Authors:
    • Dordas, C.
    • Vlachostergios, D.
    • Lithourgidis, A.
    • Damalas, C.
  • Source: European Journal of Agronomy
  • Volume: 34
  • Issue: 4
  • Year: 2011
  • Summary: Intercrops of pea ( Pisum arvense L.), a popular legume used in intercropping systems with winter cereals for forage and silage production, with wheat ( Triticum aestivum L.), rye ( Secale cereale L.), and triticale (* Triticosecale Wittmack) in two seeding ratios (60:40 and 80:20) were compared with monocrops of pea and cereals for two growing seasons. Growth rate, dry matter yield, and N uptake were determined in each intercropping system. Furthermore, several indices were used to evaluate the intercropping systems and analyze the competition and the interrelationships between mixture components. Growth rate of cereals was lower in the mixtures than in the monocrops. Dry matter yield was higher in triticale monocrop, followed by its two intercrops, and the pea-wheat 80:20 intercrop. Moreover, triticale monocrop, pea-triticale intercrops, and pea-wheat 80:20 intercrop showed the highest crude protein yield and N uptake. The land equivalent ratio (LER), relative crowding coefficient (K), actual yield loss (AYL), and system productivity index (SPI) values were greater for the pea-triticale mixtures and the pea-wheat and pea-rye mixtures (80:20), indicating an advantage of intercropping. In most intercrops, the values of partial K, AYL, aggressivity, and competitive ratio (CR) indicated that the cereal was more competitive than pea. The highest values of monetary advantage index (MAI) and intercropping advantage (IA) were recorded for the pea-triticale and the pea-wheat mixtures (80:20). Overall, pea-triticale and pea-wheat mixtures (80:20) were more productive and produced better forage quality than the other mixtures and thus could be adopted by the farmers as alternative options for forage production.
  • Authors:
    • Leap, J.
    • Klonsky, K. M.
    • Shennan, C.
    • Smith, R. F.
    • Muramoto, J.
    • Ruiz, M. S.
    • Gliessman, S. R.
  • Source: HortScience
  • Volume: 46
  • Issue: 8
  • Year: 2011
  • Summary: Legume/cereal mixed winter cover crops are commonly used by organic growers on the central coast of California, but they are unable to provide sufficient nitrogen (N) for a high N-demanding vegetable crop such as broccoli and supplemental fertilizer application may be necessary. The goals of this project were to evaluate the contribution of N from a mixed legume/cereal cover crop (CC) and feather meal and blood meal as organic fertilizers (OF) to an organic broccoli crop and to evaluate economic benefits of CC and OF to the subsequent organic broccoli crop. Trials were conducted at two sites (A and B) with different management histories. Cover crops were grown over the winter and incorporated into the soil in the spring and subsequently broccoli [ Brassica oleracea L. (Italica group)] was grown in 2006 at both sites and in 2007 at B only. Cover crop and no CC treatments were grown with supplemental organic fertilizers at four fertility levels (0, 84, 168, and 252 kg N/ha of OF) with four replicates. Generally broccoli head yields at A (14.9 to 26.3 Mg.ha -1) were higher than at B (0.7 to 17.4 Mg.ha -1 in 2006 and 5.5 to 17.9 Mg.ha -1 in 2007). Yield and aboveground biomass N were significantly increased by OF at rates up to 168 kg N/ha at A and to 252 kg N/ha at B and by CC in 2006 at both sites but not in 2007 at B. Although N content of the CC was similarly low at A (2006) and at B (2007), immobilization of soil mineral N occurred only at B. This suggests that the addition of a low N content CC was offset by high N mineralization from the soil at A with a long organic management history (greater than 33 years). Supplemental fertilizer applications may be necessary to achieve optimal yields, but the amount needed can be reduced by cover cropping in fields with a long history of cover crop-based organic management (A) or when cover crop N content is sufficiently high to prevent immobilization (B, 2006). Soil NO 3-N patterns suggest a pre-side dress nitrate test may also be useful for N management in organic broccoli. Use of cover crops increased net return above harvest and fertility costs when the yield reduction by N immobilization did not take place. However, the net return increase by the use of cover crops tended to diminish as the rate of OF application increased.
  • Authors:
    • Muchaonyerwa, P.
    • Chiduza, C.
    • Murungu, F. S.
    • Mnkeni, P. N. S.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 89
  • Issue: 1
  • Year: 2011
  • Summary: Increasing land degradation has prompted interest in conservation agriculture which includes growing cover crops. Besides providing soil cover, decaying cover crops may release substantial amounts of nutrients. Decomposition, N and P release from winter cover crops [grazing vetch ( Vicia darsycarpa), forage peas ( Pisum sativum) and oats ( Avena sativa)] were assessed for suitability in a cropping system found in the smallholder irrigation sector of South Africa. Nitrogen and P contribution to maize growth by cover crop residues was also estimated. Decrease in mass of cover crop residues was highest in grazing vetch (7% remaining mass after 124 days) followed by forage peas (16%) and lastly oats (40%). Maximum net mineralized N and P were higher for grazing vetch (84.8 mg N/kg; 3.6 mg P/kg) than for forage peas (66.3 mg N/kg; 2.7 mg P/ha) and oats (13.7 mg N/kg; 2.8 mg P/kg). Grazing vetch and forage pea residues resulted in higher N contribution to maize stover than oat residues. Farmers may use grazing vetch for improvement of soil mineral N while oats may result in enhancement of soil organic matter and reduction land degradation because of their slow decomposition. Terminating legume cover crops a month before planting summer crops synchronizes nutrient release from winter-grown legume cover crops and uptake by summer crops.
  • Authors:
    • Shabalina, E. V.
    • Korobitsyn, S. L.
    • Platunov, A. A.
  • Source: Kormoproizvodstvo
  • Issue: 1
  • Year: 2011
  • Summary: Productivity and fodder value of perennial legume and legume-grass mixtures under cover of vetch-oat mixture were studied in 2009-2010 in Kirov Region, Russia. Cover mixture consisted of spring vetch cv. Orlovskaya 4 and oat cv. Ulov with sowing rate of 0.12 and 0.06 t/ha, respectively. Red clover cv. Kirovskii 159, birds-foot trefoil cv. Solnyshko and cooksfoot cv. Khlynovskaya were used as undercrop mixture in following combinations: (1) red clover, (2) red clover + birds-foot trefoil, (3) birds-foot trefoil, (4) red clover + cooksfoot, (5) red clover + birds-foot trefoil + cooksfoot. Data on dry mass yield and number of fodder units per kg of dry mass for cover mixture and unvercover crops, as well as crude protein and cellulose content for unvercover crops are summarized in 2 tables. Productivity of cover mixture and unvercover crops varied from 3.81 to 4.18 t/ha, and from 3.86 and to 4.80 t/ha respectively with no significant difference between variants. The highest crude protein content of 17.2% was achieved in variant (3), but again with no significant difference between variants. Authors concluded that further work will be needed to achieve the high and balanced yield of cover and unvercover crops.
  • Authors:
    • Alok, T.
    • Sarawgi, S.
    • Shrikant, C.
    • Singh, M.
    • Vijendra, J.
  • Source: Journal of Soils and Crops
  • Volume: 21
  • Issue: 2
  • Year: 2011
  • Summary: Field experiment was conducted on different intercropping under irrigated condition during rabi season of 2009-10 at Indira Gandhi Krishi Vishwavidyalaya, Raipur to evaluate the yield, economics and to undertake weed studies of intercropping in rabi cereal, legume, oilseeds and spices in rice based cropping system in inceptisols. Maximum wheat equivalent yield, (65.55 q ha -1) of rabi crops was recorded in onion+coriander system over all the other intercropping treatment. Wheat+fenugreek intercropping was next in order which has also recorded significantly higher WEY (36.58 q ha -1) overwheat followed by rice, the existing cropping system (30.61 q ha -1), castor+lentil (32.78 q ha -1) and wheat+lentil (28.18 q ha -1). The highest net returns (Rs.65,292 ha -1) from rabi crops were recorded with onion+coriander because of higher value of the produce. The highest B:C ratio of rabi intercrops was recorded in onion+coriander (1.98) followed by mustard+lentil (1.90) and wheat (1.89). On the other hand, the highest weed population (172.33 and 147.00 m -2) and dry matter production (7.8 and 194 g m -2) was observed in mustard+lentil at 30 and 60 DAS. The lowest weed dry production was found in onion+coriander (1.8 g m -2) at 30 DAS, and under wheat+fenugreek (82.07 g m -2) at 60 DAS. On an average, the available N, P, K and organic carbon content were increased by 6.1, 3.6, 11.8, and 4.2%, respectively over initial values in soil after the harvest of the rabi crop.
  • Authors:
    • Macak, M.
    • Smatana, J.
  • Source: Acta Fytotechnica et Zootechnica
  • Volume: 14
  • Issue: 2
  • Year: 2011
  • Summary: The research of crop rotation pattern and field homogenization was carrying out during 2000-2010 at company Agrokarpaty Plavnica Ltd in Slovakia. The average temperature of the site during growing period is 14.9degreesC and a sum of precipitation 438 mm. The fields are situated at 300-450 m above the see level. Total acreage of arable land is 380 ha. Share of medicinal plants varied from 85 ha to 145 ha during evaluated period. The main growing medicinal and spices plants are as follows: Galega officinalis L, Medicago sativa L, Hypericum perforation L, Mentha piperita L, Melissa officinalis L, Calendula officinalis L, Fagopyrum esculentum Moench, Carum carvi L., Achilea milefolium L, Agrimonia eupatoria L, Matricaria recutita L, Plantago lanceolata L, Malva mauritiana L. As a forecrop red clover ( Trifolium pratense L), winter wheat ( Triticum aestivum L), spring barley ( Hordeum sativum L.) and oat ( Avena sativa L.) have been growing. The management practices of "Agrokarpaty Plavnica" are in full compliance with the good agricultural practices (GAP). The high priority is maintenance of soil fertility and sustain of nutrients, mainly nitrogen. The green manure, cover crop, growing of legumes and compost from own productions are used. Two steps for designing have been suggested (i) Field consolidation and homogenisation of field for crop rotations area, (ii) Proposal of crop rotation pattern. The interested area is characterized by low production potential of 8 classes of soil production categories. We have proposed new cropping pattern of 14 fields with total acreage of 180.11 ha with average field 12.87 ha. Share of medicinal and spices plants is 68.27%, share of red clover 14.29% and spring cereals 17.46%. The design of propose crop rotation allows to use organic manure mainly before medicinal plants growing for leaves drug, and incorporation of cover crops for maintenance of soil fertility. Supposed crop rotation pattern complies with basic principles of crop rotation and sustainable agriculture.
  • Authors:
    • Topp, C.
    • Walker, R.
    • Rees, R.
    • Edwards, A.
    • Baddeley, J.
    • Watson, C.
  • Source: Organic Agriculture
  • Volume: 1
  • Issue: 3
  • Year: 2011
  • Summary: The ability to maintain crop yield and quality in systems based on nitrogen (N) fixed by legumes rather than from synthetic N fertilisers is fundamental to the long-term viability of organic farming. This paper reports crop yield and nitrogen uptake parameters for the first spring oat crop after grass/clover ley in organically managed ley/arable rotations to indicate the amount of fertility built-up during the ley period. The trial site, at Tulloch in North East Scotland, underwent two complete cycles of 6-year ley/arable rotations with different lengths of grazed ley (3 or 4 years). Trials were sufficiently replicated so that each course of the rotation was present in every year. The rotation containing 3 years of ley was also compared with a similar rotation at a nearby site (Woodside) with lower rainfall and soil fertility over one and a half rotational cycles. Grain yields were consistently higher at Tulloch (5.1 tha -1 compared with 4.5 tha -1 at Woodside) and were unaffected by the length of ley. However, grain N percentage was higher following the 4-year ley (1.38% compared with 1.30% following the 3-year ley). While yields were maintained between the first and second cycles of all the rotations, grain N percentage declined. Annual grain yields of the organically grown oats at Tulloch were not significantly different from National List/Recommended List yields in NE Scotland for oats receiving 100 kg N ha -1. Results suggest that these particular rotation designs were suitable for maintaining acceptable grain yields under organic management conditions.
  • Authors:
    • Navarrete, L.
    • Kozak, M.
    • Hernandez Plaza, E.
    • Gonzalez-Andujar, J. L.
  • Source: Agriculture, Ecosystems and Environment
  • Volume: 140
  • Issue: 1-2
  • Year: 2011
  • Summary: This study investigated whether the choice of a tillage system (no-tillage, minimum tillage or traditional tillage) affected weed diversity in a 23 years cereal-leguminous rotation system in Spain. Weed diversity was assessed using common diversity indices: species richness, Shannon's index and Pielouis evenness. Linear mixed-effects models were employed to compare the tillage systems. It was found that after 23 years no large differences between tillage systems have arisen related to weed diversity. Only minimum tillage appeared to support, on average, more species than the two other tillage systems. Richness, Shannon diversity index and evenness varied largely through the years in all tillage systems but this variation was not related to type of crop sown (cereal or leguminous). Our results highlight that conservation tillage practices did not represent any concern for weed diversity conservation in cereal-leguminous rotations in the conditions of central Spain.
  • Authors:
    • Barton, L.
    • Butterbach-Bahl, K.
    • Kiese, R.
    • Murphy, D. V.
  • Source: Global Change Biology
  • Volume: 17
  • Issue: 2
  • Year: 2011
  • Authors:
    • Bojarszczuk, J.
    • Staniak, M.
    • Harasim, J.
  • Source: Journal of Research and Applications in Agricultural Engineering
  • Volume: 56
  • Issue: 3
  • Year: 2011
  • Summary: The aim of the field experiment carried out in 2007-2009 was to evaluate the yielding of pasture mixtures cultivated in organic farming. The study was conducted at the Institute of Soil Science and Plant Cultivation - Agricultural Experimental Station Grabow (Mazowia province). In the scheme of the experiment, the first factor was a dose of natural fertilization and the second factor was a percentage of legume seeds. Three doses of organic fertilization were applied as: 5, 10 and 15 t manure per 1 ha. The percentage of legumes seeds (white clover, red clover, bastard clover) in mixture was: 20, 35, 50%, the rest: Italian ryegrass, perennial ryegrass (2n), perennial ryegrass (4n), meadow bluegrass, red fescue, meadow fescue, cocksfoot, timothy. Mixtures were utilized in two ways of utilization: mown-grazed and grazed-mown system. The study showed that the highest total dry matter yields gave mixtures with 20% percentage of legume seeds in sowing, but significant differences were observed in the second year of utilization, in total yields. Differentiated organic fertilization had significant influence on dry matter yields. Increased dose of organic fertilization caused an increase of mixture yield. The combination, where legumes were sown in 20% and dose of organic fertilization was 15 t.ha -1 gave the highest dry matter yield. Differentiation of total protein yield between tested mixtures depended on organic fertilization dose. In mown-grazed utilization system, the highest total protein yields was obtained in mixtures fertilized with the dose of 15 t.ha -1 and in grazedmown utilization system - with the dose of 10 and 15 t.ha -1.