• Authors:
    • Trond M. Henriksen, T. M.
    • Anne-Kristin Løes, A.-K.
    • Sjursen, H.
    • Ragnar Eltun, R.
  • Source: Acta Agriculturae Scandinavica, Section B - Soil & Plant Science
  • Volume: 61
  • Issue: 2
  • Year: 2011
  • Summary: By restricted access to manure, nitrogen (N) supply in organic agriculture relies on biological N-fixation. This study compares grain yields after one full-season green manure (FSGM) to yields with repeated use of a green-manure catch crop. At two sites in south-eastern Norway, in a simple 4-year rotation (oats/wheat/oats/wheat), the repeated use of ryegrass, clover, or a mixture of ryegrass and clover as catch crops was compared with an FSGM established as a catch crop in year 1. The FSGM treatments had no subsequent catch crops. In year 5, the final residual effects were measured in barley. The yield levels were about equal for grains with no catch crop and a ryegrass catch crop. On average, the green-manure catch crops increased subsequent cereal yields close to 30%. The FSGM increased subsequent cereal yields significantly in two years, but across the rotation the yields were comparable to those of the treatments without green-manure catch crop. To achieve acceptable yields under Norwegian conditions, more than 25% of the land should be used for full-season green manure, or this method combined with green-manure catch crops. The accumulated amount of N in aboveground biomass in late autumn did not compensate for the N removed by cereal yields. To account for the deficiency, the roots of the green-manure catch crops would have to contain about 60% of the total N (tot-N) required to balance the cereal yields. Such high average values for root N are likely not realistic to achieve. However, measurement of biomass in late autumn may not reflect all N made available to concurrent or subsequent main crops.
  • Authors:
    • Mahajanashetti, S. B.
    • Kunnal, L. B.
    • Basavaraja, H.
    • Acharya, S. P.
    • Bhat, A. R. S.
  • Source: Agricultural Economics Research Review
  • Volume: 24
  • Issue: 2
  • Year: 2011
  • Summary: The nature and extent of crop diversification in the Karnataka state has been analyzed by collecting secondary data for a period of 26 years from 1982-83 to 2007-08. Composite Entropy Index (CEI) and multiple linear regression analysis have been used to analyze the nature and extent of crop diversification in the state. The CEI for different crop groups has shown that almost all the crop groups have higher crop diversification index during post-WTO (1995-96 to 2007-08) than during pre-WTO (1982-83 to 1994-95) period, except for oilseeds and vegetable crops. There has been a vast increase in diversification of commercial crops after WTO. Crop diversification is influenced by a number of infrastructural and technological factors. The results have revealed that crop diversification influences production. The study has suggested that the creation of basic infrastructural facilities like sustained supply of irrigation water, markets, fertilizer availability, proper roads and transportation is an essential pre-requisite for creating enabling conditions for fostering the process of agricultural development and crop diversification, as most of these parameters are found to influence the nature and extent of crop diversification.
  • Authors:
    • Aibar, J.
    • Cirujeda, A.
    • Zaragoza, C.
  • Source: Agronomy for Sustainable Development
  • Volume: 31
  • Issue: 4
  • Year: 2011
  • Summary: Management practices, geographical gradients and climatic factors are factors explaining weed species composition and richness in cereal fields from Northern and Central Europe. In the Mediterranean area, the precise factors responsible for weed distribution are less known due to the lack of data and surveys. The existence of weed survey data of year 1976 in the Zaragoza province of the Aragon region, Spain, offered us the opportunity to compare present weed species with weed species growing 30 years ago. No detailed comparison of changes in weed species composition in cereal fields in that period of time has been conducted in the Mediterranean area. Here a survey was conducted in the Aragon region from 2005 to 2007. Weeds were surveyed in 138 winter cereal fields in ten survey areas where winter cereals are the main crops, using the same methodology applied 30 years ago. In the Zaragoza province, 36 fields were chosen in the same municipalities than in the previous survey. Several management, geographic and climatic variables of each field were recorded and related to weed species with multivariate analysis. Diversity index were calculated and related to survey area and altitude. Our results show that out of the 175 species only 26 species were found in more than 10% of the surveyed fields. The main species were Papaver rhoeas, Lolium rigidum, Avena sterilis and Convolvulus arvensis found in more than half of the surveyed fields. L. rigidum was related to dryland, while the other species were found overall. Furthermore, we found that management, geographical and climatic factors were significantly related to weed species distribution. In particular altitude, survey areas, irrigation and herbicide use in post-emergence were the most driving factors explaining weed species distribution. Species richness was higher in survey areas with extensive management practices and increased with altitude excepting a very productive area with intensive management practices at high altitude where richness was as low as in the irrigated lowlands. The main differences found between the 1976 and the 2005-2007 surveys were (1) the striking increase of grass weeds, (2) the high decrease of mean weed species number found in each field declining from 9 to 3 and (3) the frequency decrease of many weed species probably caused by agriculture intensification in that period of time. The growing importance of other weed species is probably related to their adaptation to minimum tillage, which is a widespread technique nowadays.
  • Authors:
    • Tiwari, K. N.
    • Kaore, S. V.
  • Source: Fertiliser Marketing News
  • Volume: 42
  • Issue: 8
  • Year: 2011
  • Summary: Earlier, it was believed that continued and even increased use of fertilisers is essential for sustaining India's high yielding agriculture. Of late, it has been experienced that by increasing the doses of NPK through fertilisers, crop productivity cannot be sustained mainly due to decline in organic carbon content and depletion of soils nutrient reserves leading to multiple nutrients deficiencies, imbalanced use of nutrients and many more factors depending on location specific areas. This, indeed, is a major challenge to those who are concerned with agricultural development and fertiliser use in the country. The escalating prices of fertilisers and raw materials required for production of fertilisers in global market have made it necessary to search the alternatives sources giving due emphasis to renewable nutrient sources to ensure sustainable agricultural development in the country. Experience shows that the goal of sustainable agriculture can be achieved by technological manipulations blending the indigenous knowledge with modern technologies suited to specific agro-ecological regions. Integrated use of all the nutrient resources (fertilisers, organics, crop residues, biofertilisers, industrial wastes/byproducts etc.) would be essential and inevitable. At least 25% of the total nutrient needs of India can be managed with organic manures, crop residues, biofertilisers and industrial wastes. Apart from this, our focus should be on efficient land and water management coupled with responsible plant nutrient supply along with best management practices. Various components of land and water management suited to site-specific conditions need to be adopted to ensure India's food, nutrition and environmental security. This paper highlights the sustainable pathways towards greening India's "Green Revolution" for sustainable agricultural development. The salient findings of the "Soil Rejuvenation and Productivity Enhancement Project" recently initiated by the IFFCO have also been briefly elucidated in this paper.
  • Authors:
    • Bueckert, R.
    • Gan. Y.T.
    • Liu, L. P.
    • Rees, K. van
  • Source: Field Crops Research
  • Volume: 122
  • Issue: 3
  • Year: 2011
  • Summary: Oilseed and pulse crops have been increasingly used to diversify cereal-based cropping systems in semiarid environments, but little is known about the root characteristics of these broadleaf crops. This study was to characterize the temporal growth patterns of the roots of selected oilseed and pulse crops, and determine the response of root growth patterns to water availability in semiarid environments. Canola ( Brassica napus L.), flax ( Linum usitatissimum L.), mustard ( Brassica juncea L.), chickpea ( Cicer arietinum L.), field pea ( Pisum sativum L.), lentil ( Lens culinaris), and spring wheat ( Triticum aestivum L.) were tested under high- (rainfall+irrigation) and low- (rainfall only) water availability conditions in southwest Saskatchewan, in 2006 and 2007. Crops were hand-planted in lysimeters of 15 cm in diameter and 100 cm in length that were installed in the field prior to seeding. Roots were sampled at the crop stages of seedling, early-flower, late-flower, late-pod, and physiological maturity. On average, root length density, surface area, diameter, and the number of tips at the seedling stage were, respectively, 41, 25, 14, and 110% greater in the drier 2007 than the corresponding values in 2006. Root growth in all crops progressed rapidly from seedling, reached a maximum at late-flower or late-pod stages, and then declined to maturity; this pattern was consistent under both high- and low-water conditions. At the late-flower stage, root growth was most sensitive to water availability, and the magnitude of the response differed between crop species. Increased water availability increased canola root length density by 70%, root surface area by 67%, and root tips by 79% compared with canola grown under low-water conditions. Water availability had a marginal influence on the root growth of flax and mustard, and had no effect on pulse crops. Wheat and two Brassica oilseeds had greater root length density, surface area and root tips throughout the entire growth period than flax and three pulses, while pulse crops had thicker roots with larger diameters than the other species. Sampling roots at the late-flower stage will allow researchers to capture best information on root morphology in oilseed and pulse crops. The different root morphological characteristics of oilseeds, pulses, and wheat may serve as a science basis upon which diversified cropping systems are developed for semiarid environments.
  • Authors:
    • Middleton, A. B.
    • Bremer, E.
    • McKenzie, R. H.
    • Pfiffner, P. G.
    • Woods, S. A.
  • Source: Canadian Journal of Plant Science
  • Volume: 91
  • Issue: 2
  • Year: 2011
  • Summary: High crop productivity is essential for irrigated crops and may be strongly affected by decisions of seeding date and rate. An irrigated field experiment was conducted at two locations in southern Alberta for 4 yr to compare the impact of seeding date and rate on productivity and quality of nine cereal crops and two oilseed crops. Seeding rate was only evaluated on one date in late April or early May, when maximum yields were expected. Delayed seeding reduced crop yields by 0.6 to 1.7% per day after the end of April: flax ( Linum usitatissimum L.) ≤ CWRS wheat ( Triticum aestivum L.), feed triticale (* Triticosecale W.) ≤ CPS or SWS wheat ≤ triticale or barley ( Hordeum vulgare L.) silage ≤ durum ( T. turgidum L.), feed or malt barley
  • Authors:
    • Mueller, T.
    • Schulz, R.
    • Moeller, K.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 89
  • Issue: 2
  • Year: 2011
  • Summary: An increasing number of biogas plants (BGPs) based on digestion of dedicated energy crops have been implemented in Germany. The objectives of this study were to assess the changes in (1) the acreage of different crops (silage maize, cereals, etc.) related to the setup of the BGP, (2) nutrient flows and budgets (N, P, K) due to the implementation of the BGPs, and (3) to assess the effluent N in the overall crop N supply. Data from 14 farmers before the setup of the BGPs were compared with data after implementation. Due to the setup of the BGPs, the acreage of silage maize greatly increased and there were significant negative effects on the weighted soil humus budgets, no effects on the weighted mean N and P budgets, and a negative trend regarding the K budgets. Results concerning the N release from organic manuring to maize crops showed that one third of the farmers considerably over-fertilize maize, indicating an underestimation of short- and long-term N supply of manure N. The implementation of centralized BGPs established very intensive nutrient cycles and, in the long-term higher risks of nutrient losses and environmental pollution are expected. One very effective measure to compensate for negative effects on the soil humus budgets and nitrate leaching is an enlargement of cover cropping, which will also offer economic revenue by providing aboveground biomass for digestion. If the amounts of effluents returned to a single farm or field are not adapted to the nutrient composition of the substrates delivered to the BGP, large nutrient imbalances can result. An effective measure to get a better allocation of the available nutrients is a solid-liquid separation of the effluents, enabling a more targeted allocation of the nutrients.
  • Authors:
    • Rajanna, M. P.
    • Sheshshayee, M. S.
    • Mohankumar, M. V.
    • Udayakumar, M.
  • Source: ARPN Journal of Agricultural and Biological Science
  • Volume: 6
  • Issue: 7
  • Year: 2011
  • Summary: Rice is an extensively consumed cereal crop, which serves as a major source of carbohydrate in human diet. Rice cultivation requires more than 50% of the total irrigation water used for agriculture. Therefore saving irrigation water without much compromising with grain yield in rice cultivation is an important global agenda. In the present study the relevance of several drought tolerance traits in improving grain yield of rice under aerobic condition is studied. Analysis of variance indicated significant genetic variability among all plant traits. Grain yield was significantly correlated with root volume, root weight, total biomass total leaf area and Delta 13C. Path analysis indicated that root traits like root length and root weight positive direct effect on grain yield. Above ground traits like SLA, TDM, and TLA had direct positive direct effects on grain yield. The direct of Delta 13C on grain yield was negligible. Root length had highest positive indirect effect on grain yield via root volume. These results indicated that root play a pivotal role in improving grain yield. Yield displayed highest H 2BS, where as Δ 13C displayed moderate heritability among the germplasm accessions.
  • Authors:
    • Jauhiainen, L.
    • Peltonen-Sainio, P.
    • Sadras, V. O.
  • Source: Field Crops Research
  • Volume: 124
  • Issue: 2
  • Year: 2011
  • Summary: In the northernmost European environments of Finland, large variability in the yield and quality of crops is a critical source of uncertainty for growers and end-users of grain. The aims of this study were (i) to quantify and compare the plasticity, i.e., cultivar responsiveness to environment, in yield of spring oat, spring wheat, six-row barley, two-row barley, winter rye, winter wheat, turnip rape and oilseed rape, (ii) to explore the existence of hierarchies or positive correlations in the plasticity of agronomic, yield and quality traits and (iii) to probe for trends in yield plasticity associated with different eras of breeding for yield potential and agronomic traits. Plasticities of yield, agronomic and quality traits were derived as slopes of norms of reaction using MTT Agrifood Research Finland data sets combining long-term (1970-2008 for cereals and 1976-2008 for rapeseed) results from 15 to 26 locations. Plasticity of yield ranged typically between 0.8 and 1.2, was smallest for six-row barley (0.84-1.11) and largest for winter rye (0.72-1.36). We found two types of associations between plasticity of yield and yield under stressful or favourable conditions for cereals but none for rape. In spring wheat, oat and six-row barley, high yield plasticity was associated with crop responsiveness to favourable conditions rather than yield reductions under stressful conditions. Modern spring wheat cultivars had higher maximum grain yields compared to older ones at the same level of plasticity. In winter wheat and rye, high yield plasticity resulted from the combination of high yield in favourable conditions and low yield in stressful environments. Many associations between yield plasticity and other traits were identified in cereals: e.g., high yield plasticity was often associated with higher grain weight, more grains per square meter, later maturity (contrary to turnip rape), shorter plants, less lodging and lower grain protein content and in winter cereals with higher winter damage. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Pepo, P.
  • Source: Cereal Research Communications
  • Volume: 39
  • Issue: 1
  • Year: 2011
  • Summary: The interactions of ecological conditions, genotypes and agrotechnical elements determine the yield quantity, quality and stability in cereal (wheat, maize) production. The applied input-level can modify the adaptive capacity of crop models to ecological conditions. The effects of agrotechnical elements (crop rotation, fertilization, irrigation, crop protection, plant density) were studied in the long-term experiment on chernozem soil. Our scientific results proved that the high yields and good yield-stability were obtained in the input-intensive crop models, so these models had better adaptive capacity, high yield and resilience. Maize had lower ecological adaptive ability than winter wheat. The optimalization of agrotechnical elements reduces the harmful climatic effects so we can increase the yield and yield stability of cereals agro-ecosystems. The yields of wheat varied between 2 and 7 t ha -1 in extensive and 8 and 10 t ha -1 in intensive crop models and the yields of maize ranged between 2 and 11 t ha -1 and 10 and 15 t ha -1, respectively.