• Authors:
    • Matic, T.
    • Todorovic, M.
    • Albrizio, R.
    • Stellacci, A.
  • Source: Field Crops Research
  • Volume: 115
  • Issue: 2
  • Year: 2010
  • Summary: The understanding of the interactive effect of water and N availability, associated with the ability of crops to efficiently use these resources, is a crucial issue for stabilizing cereal production in Mediterranean areas. A 3-year side by side experiment on durum wheat and barley, under different water regimes and nitrogen levels, was carried out in a typical Mediterranean environment of Southern Italy, to identify the outstanding features of these species that contribute to enhanced grain yield and improved water and nitrogen use efficiency. Wheat and barley response was assessed under three water supply regimes ( I100, I50, I0: full irrigation, 50% of full irrigation and rainfed) coupled with two N fertilizer levels (high N: 120 kg ha -1 and low N: not fertilized). In order to evaluate barley yield response under lower N rates, 60 kg ha -1 were applied in 2006. The occurrence of abundant rainfall during the experimental period determined only mild water stress during most of the growing season, especially in 2006 and 2007. Under these conditions, nitrogen fertilization was the main factor affecting crop response, and different crop traits in response to irrigation were primarily evident on tissue N concentrations. Grain number per unit land area explained a high proportion of grain yield and it was mainly influenced by N fertilization. Water availability enhanced N absorption: the response of both crops to N fertilization, in terms of N uptaken and grain N concentration, was higher in the year characterized by greater water availability during the most sensitive stages to drought stress. Under unfertilized conditions, the two crops showed similar response in terms of number of grains per unit land area; under N fertilization, barley exhibited a higher increase in number of grains per unit land area, but wheat achieved similar yields as consequence of the higher grain weight. In years characterized by similar average productivity of wheat, barley did not show further increase in number of seeds, even doubling the rate of N supplied. By increasing irrigation water supply, the two crops showed a similar yield response, but a different N partition, as confirmed by the lower nitrogen harvest index values for barley over 2007-2008. At similar total availability of N, barley reached higher N utilization efficiency than wheat, mainly because of a lower N concentration in the grain rather than a higher efficiency in using the available N.
  • Authors:
    • Nazeri, A.
    • Sharif-Alhosseini, M.
    • Asadi, H.
    • Rezaei, E.
    • Faraghati, H.
  • Source: Seed and Plant Production Journal
  • Volume: 26-2
  • Issue: 1
  • Year: 2010
  • Summary: To study effects of adoption rate of application of recommended technologies in irrigated wheat production systems, this study was carried out in Neishabour region in 2005. One hundred and fifty three farmers were randomly sampled. Required data were collected using questionnaire. Depertin function was employed to estimate the impact of socio-economic factors on wheat grain yield. Breakeven analysis were performed for determination of minimum price of wheat grain. Results revealed that average seed, phosphate, potassium and urea application rates were 225, 167.3, 72.5 and 221.4 kg/ha, respectively. Average application rate for herbicides and pesticides were 1.7 and 1.4 Lit./ha, respectively. Average irrigation water used in the region was 5325 m 3/ha. Average grain and straw yields were 3451 and 2887 kg/ha, respectively. Irrigation interval and frequency were 16 days and two irrigations, respectively. However, recommended irrigation interval for the region was 10-12 days. Net profit of wheat production in machine and hand harvested systems were 952000 and 633000 rials/ha respectively. Minimum price of wheat in machine and harvested systems were 462000 and 554000 rials/ha, respectively. Coefficient of determination for variables used in the model for estimation of the effect of different inputs on wheat grain yield in Neishabour region was 0.552. Wheat producers used land, seed, labor, phosphate and irrigation water, efficiently, because the estimated elasticity of production for them varied from zero to unit. Marginal value of production for land, seed, labor, phosphate and irrigated water was estimated as 38.2, 6.5, 0.42, 3.1 and 126.6 rials/ha, respectively.
  • Authors:
    • Buresha, R.
  • Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Division Symposium 3.2 Nutrient best management practices
  • Year: 2010
  • Summary: Site-specific nutrient management (SSNM), as developed through more than a decade of research with rice ( Oryza sativa L.) in Asia, now provides scientific principles on nutrient best management practices for rice, maize ( Zea mays L.), and wheat ( Triticum aestivum L.) in Asia. These scientific principles of SSNM enable the pre-season determination of crop needs for fertilizer nitrogen (N), the within-season distribution of fertilizer N to meet crop needs, and the pre-season determination of fertilizer phosphorus (P) and potassium (K) rates to match crop needs and sustain soil fertility. Fertilizer best management for each cereal crop is tailored to field-specific conditions for crop yield, crop residue management, historical fertilizer use, use of organic materials, and nutrient inputs through irrigation water. The widespread uptake by farmers of improved nutrient management requires transforming science-based information into locally adapted tools that enable extension workers, crop advisors, and farmers to rapidly develop and implement best management practices for specific fields and growing conditions. These tools that use information technology and other means for technology dissemination include decision support software, videos, quick guides for fertilizing rice, and the leaf color chart (LCC) for managing fertilizer N.
  • Authors:
    • Talavari, F.
    • Asgharzadeh, A.
    • Dadnia, M.
  • Source: Research on Crops
  • Volume: 11
  • Issue: 3
  • Year: 2010
  • Summary: Increasing grain protein in new higher-yielding cereal grains has recently received added attention due to protein premiums paid to farmers. Winter wheat ( Triticum aestivum L.) studies were conducted during 2009 to evaluate the effects of late-season foliar N applications on grain yield. Foliar applications of N were made at spiking stage (Leaves foliar and N application with irrigation water), seed foliar and control treatments, using urea at rates of 90 and 120 kg N/ha. A significant difference in increase in grain yield was observed for leaves foliar applications in this study. In the present experiment, significant differences were observed for nitrogen levels. Consistent increases from foliar N applications were observed for grain yield. Leaves foliar applied (4 litre liquid N/ha) increased grain over that N applied with irrigation water (4 litre liquid N/ha) by 5.36 and 4.12 t/ha, respectively. Seed foliar applied (2 litre for 100 kg seed) increased grain yield than control treatments by 4.81 and 3.54 t/ha, respectively. Late-season foliar N applications before or immediately following flowering may significantly enhance grain yield content and, thus, per cent protein in winter wheat.
  • Authors:
    • Zavala-Fonseca, R.
    • Escoppinichi, R.
    • Diaz de Leon, J.
    • Castellanos, T.
    • Roder, M.
    • Mujeeb-Kazi, A.
  • Source: Cereal Research Communications
  • Volume: 38
  • Issue: 1
  • Year: 2010
  • Summary: To determine limits of tolerance, provide information about genetic diversity, and explore potential as progenitors for a salt-tolerant wheat improvement program, we collected several landraces and genotypes reputed to be salt-tolerant. Salt tolerance was tested by irrigation with a diluted solution of seawater with 12 dS.m -1 electrical conductivity for two years. Phenotypic parameters of percent of emergence, days to flowering to spike emergence, and physiological maturity were not significantly affected. Leaf area was sensitive to salt stress and inhibited about 30%. Plant height was inhibited 30%, while spike length and number of grains per spike were not. Total yield of Shorawaki and Kharchia landraces confirmed their reputation as salt-tolerant. Cultivars Mepuchi, Pericu, Calafia, WH157, and SNH-1 were inhibited at a moderate level of tolerance; cultivars Cochimi, Lu26S, and KRL 1-4 were inhibited, as was the control cultivar Oasis by up to 50%. To amplify microsatellites from genomes A, B, and D, 33 pairs of primers were used. The microsatellite WMS169-6A was highly polymorphic, with 10 different alleles distinguishing the genotype set. Also, the short arm of chromosome 4D microsatellites were amplified and found to be monomorphic, which suggests highly conserved alleles. The other microsatellites had variable polymorphism. In total, 120 alleles were obtained and used to define genetic diversity. The resulting dendrogram showed that landraces Shorawaki and Kharchia are distantly grouped from all other cultivars, as well as the cultivar Chinese Spring. Strikingly, KRL1-4, a derivative of Kharchia, did not show a close relationship to its source. The geographic origin did not influence pair-wise combinations. However, pedigree did influence pair-wise combinations.
  • Authors:
    • Chen, D.
    • Dixit, P.
  • Source: Computers and Electronics in Agriculture
  • Volume: 74
  • Issue: 2
  • Year: 2010
  • Summary: High levels of subsoil salinity limit the growth and yield of dryland cereals in the Victorian southern Mallee, Australia. Currently available crop simulation models of wheat production perform poorly in this region, presumably due to their inability to account for subsoil limitations, mainly salinity. The objective of this work was to modify a spatially referenced Water and Nitrogen Management Model (WNMM) to account for the spatial pattern of subsoil salinity, by adjusting crop water uptake, in order to explain the spatial variation in wheat yield in this area. Measurements of above-ground biomass and yield of wheat, and the profile of soil salinity (0-80 cm) were made at 40 locations across an 88 ha paddock (35.78°S, 142.98°E) in the Victorian southern Mallee. The S-shaped water stress response function for crop water uptake proposed by van Genuchten (1987) was explored to modify the WNMM by adjusting the water uptake due to salinity, which significantly improved yield simulation over the original WNMM. The improvement in the model's ability to simulate wheat yield indicates that the subsoil salinity limits crop performance in the area. The incorporation of a salinity function in spatial crop models offers potential for simulating yield across a landscape and thus practicing precision agriculture provided salinity impact is considered dynamically.
  • Authors:
    • Zhang, J.
    • Zhang, X.
    • Sun, J.
    • Kang, S.
    • Du, T.
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 1
  • Year: 2010
  • Summary: Water shortage is the major bottleneck that limits sustainable development of agriculture in north China. Crop physiological water-saving irrigation methods such as temporal (regulated deficit irrigation) and spatial (partial root zone irrigation) deficit irrigation have been tested with much improved crop water use efficiency (WUE) without significant yield reduction. Field experiments were conducted to investigate the effect of (1) spatial deficit irrigation on spring maize in arid Inland River Basin of northwest China during 1997-2000; (2) temporal deficit irrigation on winter wheat in semi-arid Haihe River Basin during 2003-2007 and (3) temporal deficit irrigation on winter wheat and summer maize in Yellow River Basin during 2006-2007. Results showed that alternate furrow irrigation (AFI) maintained similar photosynthetic rate ( Pn) but reduced transpiration rate ( Tr), and thus increased leaf WUE of maize. It also showed that the improved WUE might only be gained for AFI under less water amount per irrigation. The feasible irrigation cycle is 7d in the extremely arid condition in Inner River Basin of northwest China and less water amount with more irrigation frequency is better for both grain yield and WUE in semi-arid Haihe River Basin of north China. Field experiment in Yellow River Basin of north China also suggests that mild water deficit at early seedling stage is beneficial for grain yield and WUE of summer maize, and the deficit timing and severity should be modulated according to the drought tolerance of different crop varieties. The economical evapotranspiration for winter wheat in Haihe River Basin, summer maize in Yellow River Basin of north China and spring maize in Inland River Basin of northwest China are 420.0 mm, 432.5 mm and 450.0 mm respectively. Our study in the three regions in recent decade also showed that AFI should be a useful water-saving irrigation method for wide-spaced cereals in arid region, but mild water deficit in earlier stage might be a practical irrigation strategy for close-planting cereals. Application of such temporal and spatial deficit irrigation in field-grown crops has greater potential in saving water, maintaining economic yield and improving WUE.
  • Authors:
    • Hao, M.
    • Fan, J.
    • Malhi, S.
  • Source: Canadian Journal of Soil Science
  • Volume: 90
  • Issue: 3
  • Year: 2010
  • Summary: Nitrate (NO 3-) leaching and water contamination have become a worldwide concern. In this review, some examples are presented to show the extent and magnitude of NO 3- accumulation in the soil profiles and its potential effects on contamination of ground water and surface water under dryland farming in northern China. Climatic and management factors affecting NO 3- leaching are also discussed. In northern China, rainfall is relatively sparse, but the high intensity of precipitation and porous soils play an important role in the accumulation of NO 3N in soil and its subsequent leaching in the soil profile. There is a risk of nitrate accumulation and leaching when high rates of fertilizer N are applied to improve crop yields, and it becomes even worse when conventional land use is changed from cereal crops to vegetable crops and fruit orchards. Under such conditions, shallow ground water might be polluted by NO 3-. This suggests that more attention should be paid to prevent this problem by using best management practices, especially by controlling the amount of N fertilizer input, balanced fertilization, split N application, inclusion of crops with deep taproots in the rotation and minimizing summer fallow (especially tilled) frequency.
  • Authors:
    • Abbaspour, K.
    • Schulin, R.
    • Yang, H.
    • Faramarzi, M.
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 11
  • Year: 2010
  • Summary: In most parts of Iran, water scarcity has been intensifying and posing a threat to the sustainability of agricultural production. Wheat is the dominant crop and the largest irrigation water user in Iran; hence, understanding of the crop yield-water relations in wheat across the country is essential for a sustainable production. Based on a previously calibrated hydrologic model, we modeled irrigated and rainfed wheat yield ( Y) and consumptive water use ( ET) with uncertainty analysis at a subbasin level in Iran. Simulated Y and ET were used to calculate crop water productivity ( CWP). The model was then used to analyze the impact of several stated policies to improve the agricultural system in Iran. These included: increasing the quantity of cereal production through more efficient use of land and water resources, improving activities related to soil moisture conservation and retention, and optimizing fertilizer application. Our analysis of the ratio of water use to internal renewable water resources revealed that 23 out of 30 provinces were using more than 40% of their water resources for agriculture. Twelve provinces reached a ratio of 100% and even greater, indicating severe water scarcity and groundwater resource depletion. An analysis of Y-CWP relationship showed that one unit increase in rainfed wheat yield resulted in a lesser additional water requirement than irrigated wheat, leading to a larger improvement in CWP. The inference is that a better water management in rainfed wheat, where yield is currently small, will lead to a larger marginal return in the consumed water. An assessment of improvement in soil available water capacity ( AWC) showed that 18 out of 30 provinces are more certain to save water while increasing AWC through proper soil management practices. As wheat self-sufficiency is a desired national objective, we estimated the water requirement of the year 2020 (keeping all factors except population constant) to fulfill the wheat demand. The results showed that 88% of the additional wheat production would need to be produced in the water scarce provinces. Therefore, a strategic planning in the national agricultural production and food trade to ensure sustainable water use is needed. This study lays the basis for a systematic analysis of the potentials for improving regional and national water use efficiency. The methodology used in this research, could be applied to other water scarce countries for policy impact analysis and the adoption of a sustainable agricultural strategy.
  • Authors:
    • Xanthoulis, D.
    • Heens, B.
    • Fonder, N.
  • Source: Biotechnologie, Agronomie, Société et Environnement
  • Volume: 14
  • Issue: S1
  • Year: 2010
  • Summary: Experiments were performed over four years, testing five cultivations to optimise mineral nitrogen fertilisation when irrigation with wastewater occurs. The experimental site was located inside an irrigated perimeter around the agro-food industry Hesbaye Frost, producing frozen vegetables, in Belgium. Depending on the crop rotation adopted by the farmer, four vegetable cultivations (spinach, bean, carrot and broad bean) and one cereal (winter wheat) were tested. Because of the time required for implementation of the experiment and meteorological conditions, the irrigation factor was not tested for spinach (1999) and wheat (2000) cultivations. The two experimental factors were three fertilisation levels, with comparison to a reference without any mineral nitrogen supply, and irrigation with or without wastewater. These factors were assessed for their impacts on crop yields and mineral nitrogen residues in the soil after harvest. The three vegetable cultivations of bean, carrot and broad bean were irrigated and systematically presented statistically higher yields with wastewater irrigation supply than without. The fertilisation factor also significantly improved all the yields, or protein rate for cereal cultivation, except for carrot and broad bean where differences were not significant, even for the zero fertilisation rate. The nitrogen residues in the soil after harvest were acceptable and regular as long as the fertilisation advice was not exceeded; the maximum fertilisation level tested, 50% higher than the recommendation, systematically left unacceptable nitrogen residues in the soil, harmful for the environment. Mainly located on the top surface horizon layers, the nitrogen residues could be held back by a catch crop classified as a nitrogen trap, with the condition to be set on late summer, with fall being considered as too late to have any influence to avoid nitrogen leaching. For all fertilisation levels, nitrogen residues were too high for the broad beans cultivation because of the phenomenon of surface mineral nitrogen release, due to meteorological conditions and the wastewater high nitrogen load brought by irrigation. The nitrogen residues under conditions of no irrigation were higher than under irrigation. Irrigation allowed better nitrogen solubility, easier for uptake by the plants and thus left fewer residues in the soil.