• Authors:
    • Sainju, U. M.
    • Jabro, J. D.
    • Caesar-TonThat, T.
  • Source: Journal of Environmental Quality
  • Volume: 39
  • Issue: 3
  • Year: 2010
  • Summary: Management practices are needed to reduce dryland sod CO(2) emissions and to increase C sequestration We evaluated the effects of tillage and cropping sequence combinations and N fertilization on dryland crop biomass (stems + leaves) and sod surface CO(2) flux and C content (0- to 120-cm depth) in a Williams loam from May to October, 2006 to 2008, in eastern Montana. Treatments were no-tilled continuous malt barley (Hordeum vulgaris L) (NTCB), no-tilled malt bailey pea (Pivot; sativum L) (NTB-P), no-tilled malt barley fallow (NTB-F), and conventional-tilled malt barley fallow (CTB-F), each with 0 and 80 kg N ha(-1) Measurements were made both in Phase I (malt barley in NTCB, pea in NTB-P, and fallow in NTB-F and CTB-F) and Phase II (malt barley in all sequences) of each cropping sequence in every year Crop biomass varied among years. was greater in the barley than in the pea phase of the NTB-P treatment, and greater in NTCB and NTB-P than in NTB-F and CTB-F in 2 out of 3 yr Similarly biomass was greater with 80 than with 0 kg N ha(-1) in 1 out of 3 yr. Soil CO(2) flux increased from 8 mg C m(-2) h(-1) in early May to 239 mg C m(-2) h(-1) in mid-June as temperature increased and then declined to 3 mg C m(-2) h(-1) in September. October Fluxes peaked immediately following substantial precipitation (>10 mm). especially in NTCB and NTB-P Cumulative CO(2) flux from May to October was greater in 2006 and 2007 than in 2008, greater in cropping than in fallow phases, and greater in NTCB than in NTB-F. Tillage did not influence crop biomass and CO(2) flux but N fertilization had a variable effect on the flux in 2008. Similarly, soil total C content was not influenced by treatments Annual cropping increased CO(2) flux compared with crop fallow probably by increasing crop residue returns to sods and root and rhizosphere respiration Inclusion of peas in the rotation wills malt barley in the no-till system, which have been known to reduce N fertilization rates and sustain malt barley yields, resulted in a CO(2) flux similar to that in the CTB-F sequence
  • Authors:
    • Kennedy, A. C.
    • Schillinger, W. F.
    • Young, D. L.
    • Paulitz, T. C.
  • Source: Field Crops Research
  • Volume: 115
  • Issue: 1
  • Year: 2010
  • Summary: Field burning of residue is a traditional management tool for irrigated wheat ( Triticum aestivum L.) production in the Inland Pacific Northwest of the United States (PNW) that can result in reduced air quality. A 6-year no-till field experiment to evaluate two complete cycles of a 3-year irrigated crop rotation of winter wheat-spring barley ( Hordeum vulgare L.)-winter canola ( Brassica napus L.) was sown (i) directly into standing residue of the previous crop, (ii) after mechanical removal of residue and, (iii) after burning of residue. The traditional practice of continuous annual winter wheat sown after burning residue and inverting the topsoil with a moldboard plow was included as a check treatment. Over-winter precipitation storage efficiency (PSE) was markedly improved when residue was not burned or burned and plowed after grain harvest. Grain yield of winter wheat trended higher in all no-till residue management treatments compared to the check treatment. Average grain yields of spring barley and canola were not significantly different among the no-till residue management treatments. Winter canola failed in 5 of 6 years due to a combination of a newly identified Rhizoctonia damping-off disease caused by Rhizoctonia solani AG-2-1 and cold temperatures that necessitated replanting to spring canola. Six-year average net returns over total costs were statistically equal over all four systems. All systems lost from $358 to $396 ha -1. Soil organic carbon (SOC) increased linearly each year with no-till at the 0-5 cm depth and accumulated at a slower rate at the 5-10 cm depth. Take-all of wheat caused by Gaeumannomyces graminis var. tritici was most severe in continuous annual winter wheat. The incidence and severity of Rhizoctonia on roots of wheat and inoculum of R. solani AG-8, was highest in the no-till treatments, but there was no grain yield loss due to this disease in any treatment. Residue management method had no consistent effect on Rhizoctonia root rot on barley. The annual winter grass downy brome ( Bromus tectorum L.) was problematic for winter wheat in the standing and mechanically removed residue treatments, but was controlled in the no-till residue burned and the burn and plow check. Another winter annual grass weed, rattail fescue ( Vulpia myuros L.), infested all no-till treatments. This was the first comprehensive and multidisciplinary no-till irrigated crop rotation study conducted in the Pacific Northwest.
  • Authors:
    • Sharaiha, R.
    • Adamu, M.
  • Source: World Journal of Agricultural Sciences
  • Volume: 6
  • Issue: 6
  • Year: 2010
  • Summary: Mixed cropping of barley and durum wheat has been the practice of smallholder farmers in some drylands of Ethiopia even though the reasons for this successful cropping system were not well understood. Therefore, four planting densities, five intercrop proportions and three irrigation water levels were studied in a split-split plot arrangement in RCBD with three replications to determine the competition levels and resource use of barley and wheat mixed cropping under different growth stages. Barley was more competitive at early stages, while wheat dominated towards the reproductive stage. Intra- and inter-specific competition was decreased with increasing irrigation water levels but it was increased with increasing planting densities. Intraspecific competition was increased with increasing barley ratio in the cropping systems at all irrigation water levels, planting densities and harvesting stages. Fast growing nature of barley at early growth stages helps the intercropping system in that barley can capture belowground and areal resources faster, while wheat grows slowly and demands less resource at earlier growth stages. At later stages when wheat becomes dominant and resource demanding, early maturity of barley leaves more space for wheat to satisfy its resource demand. Thus niche differentiation index was consistently more than one in all growth stages and irrigation water levels. Therefore, mixed cropping of these two crop species helps combine important characters in a cropping system so as to enhance productivity through complementary resource uses in drylands.
  • Authors:
    • Bedoussac, L.
    • Justes, E.
  • Source: PLANT AND SOIL
  • Volume: 330
  • Issue: 1/2
  • Year: 2010
  • Summary: Grain protein concentration of durum wheat is often too low, particularly in low-N-input systems. The aim of our study was to test whether a durum wheat-winter pea intercrop can improve relative yield and durum wheat grain protein concentration in low-N-input systems. A 2-year field experiment was carried out in SW France with different fertilizer-N levels to compare wheat ( Triticum turgidum L., cv. Nefer) and pea (winter pea, Pisum sativum L., cv. Lucy) grown as sole crops or intercrops in a row-substitutive design. Without N fertilization or when N was applied late (N available until pea flowering less than about 120 kg N ha -1), intercrops were up to 19% more efficient than sole crops for yield and up to 32% for accumulated N, but were less efficient with large fertilizer N applications. Wheat grain protein concentration was significantly higher in intercrops than in sole crops (14% on average) because more N was remobilized into wheat grain due to: (i) fewer ears per square metre in intercrops and (ii) a similar amount of available soil N as in sole crops due to the high pea N 2 fixation rate in intercrops (88% compared to 58% in sole crops).
  • Authors:
    • Amri, M.
    • Fernandez-Aparicio, M.
    • Kharrat, M.
    • Rubiales, D.
  • Source: Crop Protection
  • Volume: 29
  • Issue: 7
  • Year: 2010
  • Summary: Mycosphaerella pinodes is a serious pea disease of worldwide distribution. The increasing interest of sustainable tools for disease control, together with the lack of sufficient levels of genetic resistance has brought our interest in the use of intercropping as a tool for management of this disease. Effect of intercropping on M. pinodes severity was studied in field experiments performed in Spain and Tunisia, in which a susceptible pea cultivar was grown as monocrop and as two species mixed intercrop with either faba bean, barley, oat, triticale or wheat. Disease was significantly reduced in terms of both percent of diseased tissue per plant and vertical progress of lesions when pea was intercropped. Faba bean and triticale intercropped with pea showed the highest suppressive ability with above 60% of disease reduction. Oat, barley and wheat showed low to moderate M. pinodes suppressive effects. Suppressive effects can be ascribed to a combined reduction of host biomass, altered microclimate and physical barrier to spore dispersal.
  • Authors:
    • Lajeunesse, J.
    • Pageau, D.
    • Fregeau-Reid, J.
    • Collin, J.
    • Vanasse, A.
    • Lanoie, N.
    • Durand, J.
  • Source: Canadian Journal of Plant Science
  • Volume: 90
  • Issue: 3
  • Year: 2010
  • Summary: Naked oat ( Avena sativa L.) harvested in the province of Quebec, Canada, develops on average 10% covered grains and sometimes more. The objective of this study was to determine the effect of soil type, herbicides and their application stages on the proportion of covered grains in naked oat genotypes. Three genotypes were evaluated over 2 yr at two experimental sites. At each site, trials were seeded on two different soil types and each entry was treated with one of three types of herbicides: bromoxynil/MCPA, dicamba/MCPA and thifensulfuron methyl/tribenuron methyl, and compared with a weed-free check. The herbicides were applied at Zadoks 12-13 and 22-23. Results showed that dicamba/MCPA herbicide, applied at Zadoks 12-13, increased covered grains compared with the weed-free check and more covered grains were produced with the application made at Zadoks 22-23. However, differences in genotype reactions were observed. Few differences were found among the other weed control treatments. The application of dicamba/MCPA at Zadoks 22-23 decreased yield and test weight, but increased kernel weight. The other weed control treatments had no effect on agronomic characteristics.
  • Authors:
    • Li, L.
    • Chen, W.
    • Sun, J.
    • Hu, H.
    • Yu, C.
    • Li, Q.
  • Source: Plant Nutrition and Fertilizer Science
  • Volume: 16
  • Issue: 4
  • Year: 2010
  • Summary: In a field micro-plot experiment in China of three intercropping systems (barley/maize, wheat/maize, faba bean/maize) and their corresponding sole cropping systems, nitrogen (N) was applied at N 0 and 225 kg/ha, and N absorption and use efficiency and its accumulation on the soil profile were investigated. The competitive ability of crops for nutrients was closely related to the concentration and accumulation of mineral nitrogen in the root zone of the plants. Accumulation of mineral nitrogen under barley or wheat strips intercropped with maize decreased by 203-282 or 107-171 kg/ha in the 0-100 cm soil profile, respectively, compared with faba bean intercropped with maize. Accumulation of mineral nitrogen under maize strips intercropped with barley or wheat was reduced by 93-120 or 56-87 kg/ha compared with maize intercropped with faba bean, respectively. Crop types, interspecific competition and soil condition affected accumulation of mineral nitrogen in the soil profile. Interspecific interaction increased nitrogen recovery efficiency for barley and wheat intercropped with maize and decreased that for maize intercropped with barley and wheat. Nitrogen use efficiency was the highest in the no-N treatment for competitive intercropping systems (barley/maize or wheat/maize). Nitrogen harvest index was reduced in barley and wheat with N fertilizer application, but increased in maize and not changed in faba bean. It is concluded that competition between crops, soil fertility status, fertilizer rate and cultural measures should be considered carefully in order to achieve intercropping advantage when associated crops are chosen. Complement systems of legumes/cereals are recommended for low soil fertility and competitive systems of cereals/cereals for high soil fertility.
  • Authors:
    • Lithourgidis, A.
    • Dordas, C.
  • Source: Crop Science
  • Volume: 50
  • Issue: 5
  • Year: 2010
  • Summary: Annual cool-season grain legumes like faba bean ( Vicia faba L.) grown in mixtures with winter cereals such as wheat ( Triticum aestivum L.), barley ( Hordeum vulgare L.), or rye ( Secale cereale L.) may offer advantages over cereal-alone crops grown for forage production. A 2-yr field study was conducted to evaluate the effects of intercropping faba bean with each of the above cereals in three seeding ratios (i.e., 75:25, 50:50, and 75:25) on growth rate, plant height, chlorophyll content, forage yield, and N uptake. Growth rate of faba bean and cereals was lower in the mixtures than in the monocultures, especially in the faba bean-barley mixtures because of the strong competitive ability of barley. Chlorophyll content was lower in faba bean compared with the cereals, and there was no difference among seeding ratios. Plant height of faba bean was higher in the intercrops compared with its monocrop at 3 wk after tillering (WAT), whereas at 6 WAT, the trend was different since faba bean plants in the monocrop were higher than in the intercrops. Rye monocrop and rye-faba bean intercrops provided the greatest forage yield. Although the three intercrops of faba bean with rye had lower crude protein (CP) content than the faba bean monocrop, they provided the highest CP yields per hectare because of their higher forage yield than the faba bean monocrop.
  • Authors:
    • Crozat, Y.
    • Pineau, S.
    • Corre-Hellou, G.
    • Naudin, C.
    • Jeuffroy, M. H.
  • Source: Field Crops Research
  • Volume: 119
  • Issue: 1
  • Year: 2010
  • Summary: Cereal-legume intercrops are a promising way to combine high productivity and several ecological benefits in temperate agro-ecosystems. However, the proportion of each species in the mixture at harvest is highly variable. The aim of this study was to test whether the timing of small application of N fertilizer is an effective way of influencing the dynamic interactions between species during crop growth and affecting the percentage of each species in the biomass of the mixture without greatly disturbing N 2 fixation. The influence of timing of nitrogen fertilization in pea-wheat intercrops was studied as regards (i) the dynamics of crop growth, (ii) nitrogen acquisition of each species, (iii) the inhibition and recovery of symbiotic N 2 fixation (SNF) after N application and (iv) final performance (yield, % of wheat, grain protein content). This was assessed in winter pea-wheat ( Pisum sativum L.- Triticum aestivum L.) intercrops in 2007 and 2008 at two locations in France. Whatever the stage of application, N fertilizer tended to increase wheat growth and to decrease pea growth. N fertilization (applied once at different dates from tillering to the end of stem elongation) delayed the decrease in the contribution of wheat to total biomass and maintained the competitive ability of wheat over pea for longer than in unfertilized intercrops. N acquisition dynamics and N sharing between the two species were modified by N fertilization and its timing. Crop conditions at the time of N application (growth and phenology of each species, and their proportions in the intercrop biomass) greatly influenced intercrop response to N fertilization. Partitioning between species of soil and fertilizer N was correlated with the proportion of wheat in the total intercrop biomass observed at the date of N application. Short-term inhibition of nitrates on SNF was shown during the few days after N application, whatever its date. SNF recovery after N applications was observed only until pea flowering, but was prematurely stopped by N fertilization after this stage. The effect of N fertilization on the amount of fixed N 2 at harvest was correlated with pea biomass. N fertilization affects N 2 fixation mainly by affecting crop growth rather than %Ndfa in pea-wheat intercrops. In conclusion, N fertilization could be used as a tool to enhance the contribution of wheat in the intercrop biomass but may reduce the amount of fixed N 2 in the intercrop by decreasing pea biomass.
  • 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.