• Authors:
    • Singh, R.
    • Sharma, A. R.
    • Dhyani, S. K.
    • Dube, R. K.
  • Source: Journal of Crop Improvement
  • Volume: 25
  • Issue: 4
  • Year: 2011
  • Summary: Mulching is highly beneficial for resource conservation under rainfed conditions, but non-availability of organic biomass and easy availability of fertilizers and herbicides has led to a gradual discontinuation of this practice. Various vegetative materials, including some troublesome weedy perennials, are available locally, which can be recycled for enhanced soil moisture and nutrient conservation. A field experiment was conducted at Dehradun, India, from 2001-2004 to study the effect of mulching with kudzu ( Peuraria hirsuta), wild sage ( Lantana camara), and subabul ( Leucaena leucocephala) applied at 30 and 60 days of growth of maize ( Zea mays), maize harvest, and sowing of wheat ( Triticum aestivum). Application of 10 t/ha (fresh biomass) added 1.6-2.3 t dry matter through Peuraria, 2.5-3-2 t through Lantana, and 2.9-3-9 t/ha through Leuceana, which contributed 47.7-60.9 kg N, 58.4-70.9 kg N, and 118.4-148.4 kg N/ha, respectively. All mulching materials were beneficial and improved productivity of maize significantly by 16.6-20.6% over no mulching. Wheat yield also increased because of mulching in previous maize (+11.2%), and the beneficial effect was relatively greater (12.4-25.1%) when mulching was done at maize harvest or wheat sowing. Mulching showed improvement in organic C and total N status, and a decrease in bulk density associated with an increase in infiltration rate across three cropping cycles. Wheat gave three to five times more net profit than maize, and the net benefit-cost ratio of the system was the highest (1.34-1.35) when mulching was done at 60 days of maize growth with Peuraria and Leucaena. It was concluded that mulching with available vegetative materials in standing crop of maize or after harvest was beneficial for improving moisture conservation, productivity, and profitability of a maize-wheat cropping system under Doon valley conditions.
  • Authors:
    • Sims, B. G.
    • Eliis-Jones, J.
  • Source: Agriculture for Development
  • Issue: 14
  • Year: 2011
  • Summary: This paper describes the experience of one successful no-till farm in the UK. It highlights the improved wheat yields and reduced production costs the farm has achieved over time since implementing no till; describes how it achieves no till planting and weed control; and discusses the benefits to the soil and the other environmental benefits associated with no till.
  • Authors:
    • Clark, H.
    • Molano, G.
    • Muetzel, S.
    • Hoskin, S.
    • Sun, X.
  • Source: Animal Feed Science and Technology
  • Volume: 166/167
  • Year: 2011
  • Summary: Published reports of CH 4 yields as g CH 4/kg dry matter (DM) intake suggest that emissions from sheep fed fresh forage chicory ( Cichorium intybus) are about 30% lower than from those fed fresh ryegrass. In this study, 2 year old wethers (16; 543.8 kg liveweight) were fed either mature chicory or perennial ryegrass at 1.3 times maintenance metabolisable energy requirements in the late spring/early summer of 2009. Methane emissions were determined using individual animal respiration chambers. Feeds differed in their chemical composition with chicory containing 856 g/kg organic matter (OM), 117 g/kg crude protein (CP) and 281 g/kg neutral detergent fibre (aNDF), whereas ryegrass contained 916 g/kg OM, 85 g/kg CP and 499 g/kg aNDF. The DM intake was similar for both forages at 0.76 kg/d, and CH 4 yields did not differ between forages being 22.8 and 23.8 g CH 4/kg DM intake for chicory and ryegrass, respectively. In vitro incubations of chicory and perennial ryegrass in the vegetative or mature states had similar CH 4 yields. Despite large differences in chemical composition, especially aNDF, chicory and ryegrass had similar CH 4 yields in vitro and in vivo. Chicory is not a viable alternative to perennial ryegrass for mitigating CH 4 in pastoral based sheep production systems.
  • Authors:
    • Martinez-Ruiz, C.
    • Marrs, R.
    • Alday, J.
  • Source: Journal of Vegetation Science
  • Volume: 22
  • Issue: 6
  • Year: 2011
  • Summary: Question: Does the course of succession on a coal mine restored by hydroseeding converge with a reference community in terms of species composition and vegetation structure? What is the rate of succession on restored areas? How does the balance between local colonization and extinction rates change during succession? Which species group (native or hydroseeded) determines the successional process? Location: Large reclaimed coal mine in the north of Palencia province, northern Spain (42degrees50′N, 4degrees38′W). Methods: Between 2004 and 2009 we monitored annually vascular plant species cover in nine permanent plots (20 m 2 each) at a restored mine; these plots were structured to account for site aspect (north, south and flat). Three identical permanent plots were established in the surrounding reference community and monitored in 2004 and 2009. We used detrended correspondence analysis to assess successional trends and rates of succession, generalized linear mixed models to derive patterns of vegetation structural changes and turnover through time, and Huisman-Olff-Fresco modelling to illustrate response of individual species through time. Results: The three restored mine areas exhibited a successional trend towards the reference community through time, although speed of convergence differed. However, after 6 years the restored sites had diverged considerably and this was greater than the dissimilarity reduction with respect to the reference community. Richness, diversity and native species cover increased linearly through time, whereas hydroseeded species cover decreased. Success of hydroseeded species initially differed in the three areas, and this was negatively related with native species colonization rates. Response patterns through time of ten hydroseeded and 20 most common native species are described. Conclusions: Vegetation structural parameters rapidly converged with the reference community, whereas compositional convergence needed much longer. At the same time, successional composition trajectories and rates were related to site properties (here aspect).
  • Authors:
    • Meersmans, J.
    • Poesen, J.
    • Baets, S.
    • Serlet, L.
  • Source: Catena
  • Volume: 85
  • Issue: 3
  • Year: 2011
  • Summary: Cover crops are a very effective erosion control and environmental conservation technique. When cover crops freeze at the beginning of the winter period, the above-ground biomass becomes less effective in protecting the soil from water erosion, but roots can still play an important role in improving soil strength. However, information on root properties of common cover crops growing in temperate climates (e.g. Sinapis alba (white mustard), Phacelia tanacetifoli (phacelia), Lolium perenne (ryegrass), Avena sativa (oats), Secale cereale (rye), Raphanus sativus subsp. oleiferus (fodder radish)) is very scarce. Therefore, root density distribution with soil depth and the erosion-reducing effect of these cover crops during concentrated flow erosion were assessed by conducting root auger measurements and controlled concentrated flow experiments with 0.1 m topsoil samples. The results indicate that root density of the studied cover crops ranges between 1.02 for phacelia and 2.95 kg m -3 for ryegrass. Cover crops with thick roots (e.g. white mustard and fodder radish) are less effective than cover crops with fine-branched roots (e.g. ryegrass and rye) in preventing soil losses by concentrated flow erosion. Moreover, after frost, the erosion-reducing potential of phacelia and oats roots decreased. Amoeba diagrams, taking into account both below-ground and above-ground plant characteristics, identified ryegrass, rye, oats and white mustard as the most suitable species for controlling concentrated flow erosion.
  • Authors:
    • Bedoussac, L.
    • Justes, E.
  • Source: Field Crops Research
  • Volume: 124
  • Issue: 1
  • Year: 2011
  • Summary: There are many indices available to evaluate the potential advantages of intercrops and species interactions but correct choice of index is crucial in making accurate interpretations. This study compared and evaluated the relevance in understanding intercrop functioning of some well-known indices (aggressivity, AG; cumulative relative efficiency index, REIc; land equivalent ratio, LER) and other potentially useful indices (change in contribution, CC; interspecific and intraspecific interaction index, IE and IA; comparative absolute growth rate, CGR). Data collected from a two-year field experiment in SW France with different fertiliser N levels comparing 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 were used to calculate, compare and evaluate the relevance of the selected indices for understanding intercrop functioning. It was found that AG indices (calculated with or without considering sowing density or actual plant density) did not provide the information generally claimed in the literature (i.e. whether a crop is dominant or dominated). Consequently, their use is clearly unadvisable except when analysed jointly with partial land equivalent ratios. The LER index proved to be clearly relevant, versatile and helpful in illustrating the pattern of competitive outcomes in intercropping experiments, in particular when plotting partial LER values of wheat as a function of those of pea. However, LER cannot identify intraspecific and interspecific interactions. To do so we suggest using the intraspecific and interspecific interaction indices, which can also reveal possible facilitation phenomena and allow description of species change in the contribution index (CC). Interaction dynamics between crops that determine the final balance and the outcome of all competitive interactions occurring between the two crops can be evaluated using the CGR index, which is preferable to REIc, particularly when crops differ greatly in their dry weight. Careful choice of index and interpretation of the results are thus essential in correctly understanding species interactions (globally and dynamically) and intercrop efficiency compared with sole crops. Such indices can help highlight and reveal cereal and legume traits suited to intercropping and also appropriate cropping sequences and management techniques, allowing efficient intercropping. However, the results must always be related to actual data values (yield, dry weight or N accumulated) because the indices used cannot evaluate intrinsically quantitative performance but only the relative performance of intercrops compared with that of sole crops.
  • Authors:
    • Montfort, F.
    • Faloya, V.
    • Schlaunich, E.
    • Aubree, N.
    • Breton, D.
  • Source: 4eme Conference Internationale sur les Methodes Alternatives en Protection des Cultures.
  • Year: 2011
  • Summary: To study the interest and the limits of the insertion of various cover crop with biofumigation potential in a crop succession, three trials, one in Aquitaine (40), one in Normandy (50) and one in Rheu (35) were performed on two important soilborne diseases of carrot: cavity-spot due to Pythium sulcatum or the brown rot disease due to Rhizoctonia solani. Intercrop plants were cultivated then crushed and incorporated in the soil one month before carrot crop. In the three trials, the effect of the mustard Brassica juncea on the incidence and the severity of the diseases is studied and compared with bare soil. In the Normandy trial, two other cover crops are also studied: oat and rye crop. In Le Rheu trial, regular observations allow to compare the development of cavity-spot over time after insertion then incorporation of a mustard crop or after a bare soil. The results are presented; the technical feasibility and the impact of method on disease development are discussed.
  • Authors:
    • Ladewig, E.
    • Schulte, M.
    • Schmitz, F.
    • Burcky, K.
    • Buhre, C.
  • Source: Sugar Industry / Zuckerindustrie
  • Volume: 136
  • Issue: 10
  • Year: 2011
  • Summary: Since 1994, data on sugarbeet production in Germany are continuously collected in annual cultivation surveys based on the information from the German sugar factories. Because of the long-term data set, many developments over the last years as well as short-term adaptations could be described. Cereals, particularly winter wheat, are the main pre-crop before sugarbeet (50%), followed by maize. Intercrops have been cultivated on 40% of the sugarbeet area since the beginning of the survey. The use of reduced systems increased in soil cultivation. The soil is covered by intercrops or pre-crop residues on more than 65% of the sugarbeet area. Since 2006, an increase in nitrogen fertilization was observed. Organic fertilizer was applied on 50% of the sugarbeet area. Crop production, from sowing to harvesting is characterized by an increase in technical specialization. The survey is conducted in cooperation with the farmers, or by specialized contractors. The beets are harvested mainly with six-row harvesters and transported increasingly with semi-trailer trucks.
  • Authors:
    • Piepho, H.
    • Hartung, K.
    • Graeff-Honninger, S.
    • Grozinger, H.
    • Knorzer, H.
    • Claupein, W.
  • Source: Field Crops Research
  • Volume: 121
  • Issue: 2
  • Year: 2011
  • Summary: Wheat/maize related multi-cropping systems are the dominant cropping systems in North China. To improve and adjust those systems, and to study competition effects within intercropping, extended field experiments are necessary. As field experiments are time consuming, laborious and expensive, a viable alternative is the use of crop growth models that can quantify the effects of management practices on crop growth and productivity. Field experiments showed that intercropped maize yielded as high as monocropped maize, and grain yield of intercropped wheat increased by up to 32%. Based on a process-oriented modeling approach, this study focuses on analyzing and modeling competitive relationships in a wheat/maize relay intercropping system with regard to yield, solar radiation and microclimate effects. A simple shading algorithm was applied and integrated into the CERES models, which are part of the DSSAT software shell vs. 4.5. The algorithm developed estimates the proportion of shading as affected by neighbouring plant height. The model was tested to investigate the applicability of this shading algorithm within the CERES models in the simulation of grain yield and dry matter yield of wheat and maize. Model error of grain and dry matter yield for both species was below 10%. There was a tendency for grain yield to be simulated adequately but for dry matter yield to be slightly underestimated. Increased top soil temperature in intercropped wheat increased the mineralization of nitrogen and improved N supply. The wheat/maize system was N efficient. Thus, N dynamics were taken into account for simulation as well as CO 2 dynamics based upon modified wind speed. Wheat border rows were exposed to a higher wind speed until mid-June and to reduced wind speed thereafter. As a result, solar radiation, soil temperature and wind speed differed between monocropping and intercropping and could provide a starting point for simulating intercropping. Microclimate effects are often small, subtle or non-existent, while spatial and climate variability and the heterogeneity of plant populations can be considerable. Quantifying microclimatic effects may prove difficult but should not be neglected when simulating intercropping systems.
  • Authors:
    • Hermansen, J.
    • Panneerselvam, P.
    • Halberg, N.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 1
  • Year: 2011
  • Summary: This study compared farm production, crop yield, input cost, and income in organic and conventional farming systems in three states of India: Uttarakhand, Madhya Pradesh, and Tamil Nadu. The results showed that organic farming reduced the input cost without affecting the net margin in all three states. Total food production was found to be comparable for the two systems in two of three states. While yield of rice and wheat generally was lower under the organic systems, yield from intercropping food crops was generally higher. The number of agro-ecological methods and percentage of farms practicing different agro-ecological methods were higher under organic systems than conventional systems. These results suggest that organic farming has the potential to improve food security of small farmers by reducing indebtedness due to the lower cost of production without affecting total farm production and farm income.