• Authors:
    • Naranjani, L.
    • Shahrajabian, M. H.
    • Soleymani, A.
  • Source: Journal of Food, Agriculture and Environment (JFAE)
  • Volume: 9
  • Issue: 1
  • Year: 2011
  • Summary: Population growth and the consequent pressure on land resources and frequent crop failures have led to greater land use as well as intercropping systems. In order to investigate the changes of ash percentage, important elements and solar radiation absorption of three cultivars of berseem clover as cover crops intercropped with forage corn in different levels of nitrogen starter fertilizer, an experiment was conducted in 2010, at Research Farm, Faculty of Agriculture, Islamic Azad University, Khorasgan Branch (Isfahan). A factorial layout within randomized complete block design with 3 replications was used. Cultivars were Karaj, Sacromont and Multicut, and nitrogen levels included 0, 40 and 60 kg/ha. The nitrogen fertilizer was provided from urea source (46% pure N). Cultivar had significant effect on ash percentage and solar radiation absorption. The effect of nitrogen also was significant on ash percentage, Fe content, Mn content and solar radiation absorption. Ash percentage, Fe content, solar radiation absorption and light transmission were significantly influenced by interaction between cultivar and nitrogen. The highest ash percentage, Fe and Zn content were related to Sacromont. The maximum Mn content, Cu content and light transmission were obtained by Multicut. The maximum solar radiation absorption was related to Karaj. The nutritive value of berseem clover was influenced by changes in different levels of nitrogen starter fertilizer. The highest ash percentage, Mn content, Cu content and light transmission was obtained by application of 40 kg N/ha. The maximum Zn content was related to application of 60 kg N/ha. Control treatment had the maximum Fe content and solar radiation absorption.
  • Authors:
    • Sediyama, G. C.
    • Moura, M. S. B. de
    • Souza, L. S. B. de
    • Silva, T. G. F. da
  • Source: Bragantia
  • Volume: 70
  • Issue: 3
  • Year: 2011
  • Summary: This study aimed to analyze the productivity, the water use efficiency, and the economical viability for corn and cowpea crops on single and intercropping systems in the Brazilian semiarid region. The experiment was carried out at Petrolina, State of Pernambuco. The crops, in different planting systems (single and intercropping), underwent the five blades of irrigation, applied at the flowering stage of cowpea to 40 days after sowing. Combining the settings of cultivation system and the different depths of irrigation, crops of maize and cowpea were subjected to 15 different treatments. To evaluate the performance of crops in the different treatments indicators that consider the production response of crops and the performance of the application of water in the production system were used. The grain yield responses of maize and cowpea to the soil water content were reduced in intercropped plantations, in relation to single cropping. Even so, in economic terms, the adoption of maize-cowpea proved to be more advantageous in all treatments.
  • Authors:
    • LaFond, G. P.
    • May, W. E.
    • Tenuta, M.
    • Entz, M. H.
    • Turmel, M. S.
  • Source: Canadian Journal of Plant Science
  • Volume: 91
  • Issue: 6
  • Year: 2011
  • Summary: Leguminous cover crops are becoming a popular way to increase the sustainability of agricultural systems. Previously, cover crops have been found to increase colonization by arbuscular mycorrhizal fungi (AM F) and phosphorus and micronutrient uptake. Long-term field studies were conducted to test the hypothesis that self-regenerating black medic (Medicago lupulina cv. George) cover crops increase AM F colonization and early nutrient uptake in flax (Linum usitatissimum). Field experiments were established in 2000 (Manitoba) and 2002 (Saskatchewan) using a flax wheat (Triticum aestivum) oat (Avena sativa) rotation. In a second experiment, intact soil cores were harvested from the plots in spring and tested for soil disturbance and cover crop effects under controlled environment conditions (CEC). Both seedling flax crops sampled from the field in 2005 and 2006 and flax growth in CEC showed high levels of AMF root colonization, but no significant influence of the cover crop on AM F colonization by arbuscules or hyphal structures was detected. The AMF enhancing practices used in the experiments (i.e., zero-tillage and inclusion of mycorrhizal crops) may have contributed to the lack of cover crop effect on AMF colonization. The cover crop had no effect on macro- or micronutrient uptake by flax except during drought conditions (Winnipeg 2006), where flax biomass was reduced by 38% and the total uptake of N, P, Zn and Cu was decreased by 34, 30, 31 and 35%, respectively, in the medic treatment.
  • Authors:
    • Vinnichek, L.
    • Ivanov, A.
  • Source: Mezhdunarodnyi Sel'skokhozyaistvennyi Zhurnal
  • Issue: 5
  • Year: 2011
  • Summary: In Russia's Penza Oblast', cereal grain crops account for 58.1% of receipts from crop sales, sugarbeets account for 26.9%, and oil bearing crops 5.8%. Penza Oblast' can be divided into four different zones, each of which is characterized by different patterns of crop production. These zones are: (1) Vadinskii-Mokshanskii, comprising 12 raiony (administrative districts) in the Central and North Western parts of the oblast'; (2) Belinskii-Serdobskii, comprising seven raiony in the South and South West of the oblast'; (3) Nikol'skii-Gorodishchenskii, comprising three raiony in the North East of the oblast'; and (4) Kuznetskii-Lopatinskii, comprising five raiony in the South East and East of the oblast'. Zone (1) is characterized by average productivity soils, and includes 48.8% of the total land area used for cereal grain production in the oblast', 50.6% of land used for sugarbeet production, and 23.6% of land used for sunflower cultivation. Zone (2) has the highest productivity soils in the oblast', and accounts for 35.0% of the total land area used for cereal grain production in the oblast' and 49.4% of land used for sugarbeet cultivation in the oblast'. The fertility of most soils in zone (3) is poor, resulting in low productivity. Zone (3) accounts for just 4.0% of the total land area used for cereal grain production in the oblast', and technical crop production in this zone is almost nonexistent. Zone (4) accounts for 12.1% of the total land area used for cereal grain production in the oblast' and 31.5% of land used for sunflower cultivation. Sugarbeets are not grown in zone (4) because of the distance from sugar refineries. The zones in which crop production is most profitable are zones (1) and (2), which are also characterized by the highest degree of diversification. Overall, the most economically efficient crop types produced in the Oblast' are potatoes and sunflowers. Recommendations for the future development of different types of crop production in have been formulated on the basis of analysis of natural and economic factors existing in different parts of the oblast'. The recommendations relate to the cultivation of different cereal grain crops (including winter and summer wheat, barley, buckwheat, maize, rye and oats), legume crops (peas and lentils), sugarbeets, oil bearing crops (sunflowers, rape and camelina), potatoes, and other vegetables in the four different zones.
  • Authors:
    • Dobermann, A. R.
    • Shapiro, C. A.
    • Tarkalson, D. D.
    • Wortmann, C. S.
    • Ferguson, R. B.
    • Hergert, G. W.
    • Walters, D.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 1
  • Year: 2011
  • Summary: Nitrogen use efficiency (NUE) is of economic and environmental importance. Components of NUE were evaluated at in 32 irrigated corn (Zea mays L.) trials conducted across Nebraska with different N rates and where the previous crop was either corn (CC), drybean ( Phaseolus vulgaris L.) (CD), or soybean [Glycine max (L.) Merr.] (CS). The mean grain yield with adequate nutrient availability was 14.7 Mg ha -1 When no N was applied, measured soil properties and irrigation water N accounted for <20% of the variation in plant nitrogen uptake (UN). Mean fertilizer N recovery in aboveground biomass was 74% at the lowest N rate compared with 40% at the highest N rate, a mean of 64% at the economically optimal nitrogen rate (EONR), and least with CD. Agronomic efficiency of fertilizer N averaged 29 kg grain kg(-1) N at EONR and was also least with CD. Partial factor productivity of N averaged 100 kg grain kg(-1) N at EONR, and was greater with CS compared with CC and CD. Aft er harvest, residual soil nitrate nitrogen (RSN) in the 0- to 1.2-m depth ranged from 21 to 121 kg ha(-1) and increased with N rate. Mean RSN was 88, 59, and 59 kg ha(-1) for CD, CC, and CS, respectively. High corn yields can be achieved with high NUE and low RSN by management to maximize profitability in consideration of yield potential, and by applying N at the right amount and time.
  • Authors:
    • Zhang, Y. J.
    • Liu, R. T.
    • Zhu, X. Y.
  • Source: African Journal of Biotechnology
  • Volume: 10
  • Issue: 45
  • Year: 2011
  • Summary: A field experiment was conducted on an infertile red soil under a hairy vetch (Vicia villosa Roth) and corn (Zea mays L.) rotation system in a highland area of Yunnan Province, China. Effects of phosphate (P) fertilization, combined with hairy vetch returned to the soil, on crop yield and soil fertility were studied, and the balances of nitrogen (N), phosphorus (P) and potassium (K) in the rotation system were estimated. As P application increased from 135 to 315 kg ha(-1), the dry matter yield of hairy vetch increased by 900.6 to 1283.86 kg DM ha(-1), and also promoted P absorption by hairy vetch. When compared with CK, the corn and corn straw yield increased by 16.64 and 33.48%, respectively, from the crop rotation system, while it increased by 18.36 and 34.96% and 32.58 and 66.5%, from the integrated use of green manure and P fertilizer, respectively. Simple crop rotation proceeding could improve soil N content in the 0 to 20 cm soil layer, while the combined P application improved soil P content. After corn harvest, soil Olsen-P content under the different treatments increased by 35.31 and 122.15% and 19.70 and 63.63% in the 0 to 10 and 10 to 20 cm soil layers, respectively. The optimum P fertilizer rate for the hairy vetch-corn rotation system in Yunnan Province was 135 kg P2O5 ha(-1). At this P rate, the nutrient balance surpluses for N, P and K were 84.9, 18.9 and 26.4%, respectively.
  • Authors:
    • Zuo, Y. M.
    • Zhang, F. S.
  • Source: Plant and Soil
  • Volume: 339
  • Issue: 1/2
  • Year: 2011
  • Summary: Plants and humans cannot easily acquire iron from their nutrient sources although it is abundant in nature. Thus, iron deficiency is one of the major limiting factors affecting crop yields, food quality and human nutrition. Therefore, approaches need to be developed to increase Fe uptake by roots, transfer to edible plant portions and absorption by humans from plant food sources. Integrated strategies for soil and crop management are attractive not only for improving growing conditions for crops but also for exploiting a plant's potential for Fe mobilization and utilization. Recent research progress in soil and crop management has provided the means to resolve complex plant Fe nutritional problems through manipulating the rhizosphere (e.g., rhizosphere fertilization and water regulation), and crop management (includes managing cropping systems and screening for Fe efficient species and varieties). Some simple and effective soil management practices, termed 'rhizosphere fertilization' (such as root feeding and bag fertilization) have been developed and widely used by local farmers in China to improve the Fe nutrition of fruit plants. Production practices for rice cultivation are shifting from paddy-rice to aerobic rice to make more efficient use of irrigation water. This shift has brought about increases in Fe deficiency in rice, a new challenge depressing iron availability in rice and reducing Fe supplies to humans. Current crop management strategies addressing Fe deficiency include Fe foliar application, trunk injection, plant breeding for enriched Fe crop species and varieties, and selection of cropping systems. Managing cropping systems, such as intercropping strategies may have numerous advantages in terms of increasing Fe availability to plants. Studies of intercropping systems on peanut/maize, wheat/chickpea and guava/sorghum or -maize increased Fe content of crops and their seed, which suggests that a reasonable intercropping system of iron-efficient species could prevent or mitigate Fe deficiency in Fe-inefficient plants. This review provides a comprehensive comparison of the strategies that have been developed to address Fe deficiency and discusses the most recent advance in soil and crop management to improve the Fe nutrition of crops. These proofs of concept studies will serve as the basis for future Fe research and for integrated and optimized management strategies to alleviate Fe deficiency in farmers' fields.
  • Authors:
    • Maldaner, G. L.
    • Spera, S. T.
    • Fontaneli, R. S.
    • dos Santos, H. P.
  • Source: PESQUISA AGROPECUARIA BRASILEIRA
  • Volume: 46
  • Issue: 10
  • Year: 2011
  • Summary: The objective of this work was to assess energy conversion and balance of integrated crop-livestock production systems, under no-tillage. The experiment was carried out from 2001 to 2008. From 2001 to 2002, the following systems were evaluated: 1, wheat/soybean, and black oat pasture+common vetch/corn; 2, wheat/soybean, and black oat pasture+common vetch+ryegrass/corn; 3, wheat/soybean and black oat pasture+common vetch/millet pasture; 4, wheat/soybean and black oat pasture+common vetch+rygrass/millet pasture; 5, wheat/soybean, white oat/soybean, and black oat pasture+common vetch/millet pasture; 6, wheat/soybean, white oat/soybean, and black oat pasture+common vetch+rygrass/millet pasture. From 2003 to 2008, the following systems were evaluated: 1, wheat/soybean, and common vetch/corn; 2, wheat/soybean, and black oat pasture/corn; 3, wheat/soybean, and black oat pasture/soybean; 4, wheat/soybean, and field pea/corn; 5, wheat/soybean, common vetch/soybean, and double purpose triticale/soybean; and 6, wheat/soybean, double purpose white oat/soybean, and double purpose wheat/soybean. Corn showed highest returned energy in comparison to the other grain crops, and to winter and summer annual pastures. Of the winter cover crops and green manure species evaluated, field pea was the most efficient in energy conversion. Systems 1, 2, and 4, from 2003 to 2008, had the most efficient energy balance.
  • Authors:
    • Rao, I. M.
    • Schmidt, A.
    • van der Hoek, R.
    • Bernasconi, S. M.
    • Frossard, E.
    • Douxchamps, S.
    • Oberson, A.
  • Source: Plant and Soil
  • Volume: 341
  • Issue: 1-2
  • Year: 2011
  • Summary: The integration of multipurpose legumes into low-input tropical agricultural systems is needed because they are a nitrogen (N) input through symbiotic fixation. The drought-tolerant cover legume canavalia (Canavalia brasiliensis) has been introduced for use either as forage or as a green manure into the crop-livestock system of the Nicaraguan hillsides. To evaluate its impact on the subsequent maize crop, an in-depth study on N dynamics in the soil-plant system was conducted. Microplots were installed in a 6-year old field experiment with maize-canavalia rotation. Direct and indirect (15)N-labelling techniques were used to determine N uptake by maize from canavalia residues and canavalia-fed cows' manure compared to mineral fertilizer. Litter bags were used to determine the N release from canavalia residues. The incorporation of N from the amendment into different soil N pools (total N, mineral N, microbial biomass) was followed during the maize cropping season. Maize took up an average of 13.3 g N m(-2), within which 1.0 g N m(-2) was from canavalia residues and 2.6 g N m(-2) was from mineral fertilizer, corresponding to an amendment N recovery of 12% and 32%, respectively. Recoveries in maize would probably be higher at a site with lower soil available N content. Most of the amendment N remained in the soil. Mineral N and microbial N were composed mainly of N derived from the soil. Combined total (15)N recovery in maize and soil at harvest was highest for the canavalia residue treatment with 98% recovery, followed by the mineral fertilizer treatment with 83% recovery. Despite similar initial enrichment of soil microbial and mineral N pools, the indirect labelling technique failed to assess the N fertilizer value of mineral and organic amendments due to a high N mineralization from the soil organic matter.
  • Authors:
    • Linden, B.
    • Aronsson, H.
    • Stenberg, M.
    • Engstrom, L.
  • Source: Agronomy for Sustainable Development
  • Volume: 31
  • Issue: 2
  • Year: 2011
  • Summary: Nitrate leaching after winter oilseed rape and peas has not been studied at the most northern limits of oilseed rape cultivation where winters vary between being mild, with continuous drainage, and cold, with periods of frozen soil. Here, we studied the effect of N fertilisation to oilseed rape, catch crops after oilseed rape and peas and dired drilling of winter wheat after oilseed rape on N leaching in south-west Sweden. Nitrate leaching was determined in two field experiments, dated 2004-2006 and 2005-2007, respectively, on a sandy loam. Our results show that under oilseed rape nitrate leaching was low, at 16-23 kg N ha(-1), in a mild winter with drainage from October to March. In the subsequent mild winter nitrate leaching under wheat was higher, amounting to 35-94 kg N ha(-1). Nitrate leaching levels were similar, 32-58 kg N ha(-1), for all crops in a cold winter with a long-lasting snow cover and main drainage occurring after snowmelt in March and April. Application of fertiliser N to oilseed rape at the optimum N rate, rather than 50 kg N ha(-1) above optimum, reduced leaching in a following winter wheat crop by 25 and 27 kg N ha(-1) in a cold and a mild winter, respectively. Spring undersowing of perennial ryegrass as a catch crop reduced leaching by 12 kg N ha(-1) after optimally fertilised oilseed rape in a mild winter, despite only growing until mid-September when winter wheat was sown. An undersown catch crop of peas, then grown until November, reduced leaching by 15 kg N ha(-1). Direct drilling of winter wheat after oilseed rape had no effect. These findings show that there are risks of enhanced leaching in early spring after a cold winter with a snow cover and superficially frozen soil. Optimising the spring N rate for oilseed rape was the most effective measure to decrease leaching in both mild and cold winters, and this effect was improved by an undersown catch crop in a mild winter.