• Authors:
    • Orhan, I.
    • Coksari, G.
    • Kan, A.
    • Senol, F.
  • Source: International Journal of Food Sciences and Nutrition
  • Volume: 63
  • Issue: 5
  • Year: 2012
  • Summary: The ethyl acetate and ethanol extracts obtained from eight varieties (Faikbey, Y-1779, CI-8357, Cheokota, Seydisehir, Y-330, Sivas and YVD-18) of oat ( Avena sativa L.), one variety (Larende) of barley ( Hordeum vulgare L.), one variety (Tatlicak 97) of triticale ( Triticale sp.) and one rye variety (Aslim 95) ( Secale cereale L.) were investigated for their antioxidant effects in seven test systems. Anticholinesterase activity of the extracts was examined by enzyme-linked immunosorbent assay (ELISA) microplate reader. Total phenol and flavonoid contents were calculated using Folin Ciocalteau and AlCl 3 reagents, respectively. All of the extracts were ineffective in cholinesterase inhibition assays and had weak-to-moderate activity in antioxidant assays. The extracts exerted better activity in iron-chelation capacity ranging between 43.172.04 and 62.971.29%. Triticale extracts showed higher activity in reducing power experiments. A notable difference in the results of the antioxidant activity assays was observed among the oat varieties.
  • Authors:
    • Szendrei, Z.
  • Source: Entomologia Experimentalis et Applicata
  • Volume: 143
  • Issue: 2
  • Year: 2012
  • Summary: Habitat diversification can influence the interactions of insects with plants and this can be used in agroecosystems for the management of pest populations. Plant diversification can be achieved through planting crops, such as trap crops, or by adjusting weed management. Aster leafhopper, Macrosteles quadrilineatus Forbes (Hemiptera: Cicadellidae), is a polyphagous species that uses cereals, vegetables, and weeds as host plants. The influence of weeds on M. quadrilineatus abundance was investigated experimentally in carrot [ Daucus carota L. cv. Canada (Apiaceae)] field plots by adjusting the level of management of two groups of weeds (broadleaf and grass) and by comparing it to weed-free plots. The preference of M. quadrilineatus for different cereal and weed species relative to carrots was tested in choice test assays. Habitat context influenced the abundance of M. quadrilineatus in the field experiments. The presence of border crops such as oat, rye, barley, wheat, and triticale did not significantly attract or repel this insect to carrot plots compared to the no-border treatment. However, spelt-bordered plots had 42% fewer M. quadrilineatus than three treatments, triticale, wheat, and barley, that had the highest insect abundance. The type of weed management affected M. quadrilineatus abundance in carrot plots, but not the frequency of herbicide application. Plots that had carrot growing with broadleaf-weeds had about 59% fewer M. quadrilineatus compared with those growing with crabgrass or carrot alone. In the greenhouse choice tests, grasses (e.g., cereals) attracted and broadleaf-weeds repelled M. quadrilineatus relative to carrots. In summary, carrot growers may be able to manage this pest by reducing the interaction of cereal cover crops with carrots and eliminating grassy weeds in commercial production fields.
  • Authors:
    • Cao, L.
    • Lobell, D. B.
    • Pongratz, J.
    • Caldeira, K.
  • Source: Nature Climate Change
  • Volume: 2
  • Issue: 2
  • Year: 2012
  • Summary: Crop models predict that recent and future climate change may have adverse effects on crop yields(1,2). Intentional deflection of sunlight away from the Earth could diminish the amount of climate change in a high-CO2 world(3-6). However, it has been suggested that this diminution would come at the cost of threatening the food and water supply for billions of people(7). Here, we carry out high-CO2, geoengineering and control simulations using two climate models to predict the effects on global crop yields. We find that in our models solar-radiation geoengineering in a high-CO2 climate generally causes crop yields to increase, largely because temperature stresses are diminished while the benefits of CO2 fertilization are retained. Nevertheless, possible yield losses on the local scale as well as known and unknown side effects and risks associated with geoengineering indicate that the most certain way to reduce climate risks to global food security is to reduce emissions of greenhouse gases.
  • Authors:
    • Kuzyakov, Y.
    • Li, X.
    • Marschner, P.
    • Guo, J.
    • Fan, M.
    • Tian, J.
  • Source: European Journal of Soil Biology
  • Volume: 52
  • Issue: September–Octobe
  • Year: 2012
  • Summary: In the last three decades there has been a major shift in China's agriculture with the conversion from cereal fields to vegetable production, however little is known about the impact of this land use change on labile soil carbon and microbial community structure. We conducted a study to characterize dissolved organic carbon (DOC) and soil microbial community by comparing greenhouse vegetable fields with contrasting management intensity and adjacent cereal fields (wheat maize rotation) in Shouguang and Quzhou in North China. Compared with cereal fields, greenhouse vegetable cultivation increased soil organic carbon (SOC) and total nitrogen (TN), while it decreased the soil pH, particularly at the high-intensity site. The DOC concentration was significantly higher in greenhouse vegetable fields than in cereal fields, whereas DOC composition differed between greenhouse vegetable fields and cereal fields only at high management intensity. Chemical fractionation indicated that DOC from greenhouse vegetable fields with high management intensity was less decomposed than DOC from cereal fields, because the percentage of hydrophobic acid (HOA) as DOC was higher in vegetable fields. Vegetable production significantly changed the microbial community structure in comparison to cereal fields: high-intensity management increased total bacteria, G (+) bacteria and fungi, while low-intensity decreased fungi and increased bacteria-to-fungi ratio. The main factor affecting microbial community structure was soil pH in this study, accounting for 24% of the differences. (C) 2012 Elsevier Masson SAS. All rights reserved.
  • Authors:
    • Fernando, L. K.
    • Banuwa, I. S.
    • Buchari, H.
    • Utomo, M.
    • Saleh, R.
  • Source: Journal of Tropical Soils
  • Volume: 17
  • Issue: 1
  • Year: 2012
  • Summary: Although agriculture is a victim of environmental risk due to global warming, but ironically it also contributes to global greenhouse gas (GHG) emission. The objective of this experiment was to determine the influence of long-term conservation tillage and N fertilization on soil carbon storage and CO2 emission in corn-soybean rotation system. A factorial experiment was arranged in a randomized completely block design with four replications. The first factor was tillage systems namely intensive tillage (IT), minimum tillage (MT) and no-tillage (NT). While the second factor was N fertilization with rate of 0, 100 and 200 kg N ha -1 applied for corn, and 0, 25, and 50 kg N ha -1 for soybean production. Samples of soil organic carbon (SOC) after 23 year of cropping were taken at depths of 0-5 cm, 5-10 cm and 10-20 cm, while CO2 emission measurements were taken in corn season (2009) and soybean season (2010). Analysis of variance and means test (HSD 0.05) were analyzed using the Statistical Analysis System package. At 0-5 cm depth, SOC under NT combined with 200 kg N ha -1 fertilization was 46.1% higher than that of NT with no N fertilization, while at depth of 5-10 cm SOC under MT was 26.2% higher than NT and 13.9% higher than IT. Throughout the corn and soybean seasons, CO2-C emissions from IT were higher than those of MT and NT, while CO2-C emissions from 200 kg N ha -1 rate were higher than those of 0 kg N ha -1 and 100 kg N ha -1 rates. With any N rate treatments, MT and NT could reduce CO2-C emission to 65.2%-67.6% and to 75.4%-87.6% as much of IT, respectively. While in soybean season, MT and NT could reduce CO2-C emission to 17.6%-46.7% and 42.0%-74.3% as much of IT, respectively. Prior to generative soybean growth, N fertilization with rate of 50 kg N ha -1 could reduce CO2-C emission to 32.2%-37.2% as much of 0 and 25 kg N ha -1 rates.
  • Authors:
    • Xiong, Z.
    • Zhang, X.
    • Liu, Y.
    • Pan, X.
    • Wang, J.
  • Source: Plant and Soil
  • Volume: 360
  • Issue: 1-2
  • Year: 2012
  • Summary: Worldwide, there is an increasing interest in using biochar in agriculture to help mitigate global warming and improve crop productivity. The effects of biochar on greenhouse gas (GHG) emissions and rice and wheat yields were assessed using outdoor pot experiments in two different soils (upland soil vs. paddy soil) and an aerobic incubation experiment in the paddy soil. Biochar addition to the upland soil increased methane (CH4) emissions by 37 % during the rice season, while it had no effect on CH4 emissions during the wheat season. Biochar amendment decreased nitrous oxide (N2O) emissions up to 54 % and 53 % during the rice and wheat seasons, respectively, but had no effect on the ecosystem respiration in either crop season. In the aerobic incubation experiment, biochar addition significantly decreased N2O emissions and increased carbon dioxide (CO2) emissions from the paddy soil (P < 0.01) without urea nitrogen. Biochar addition increased grain yield and biomass if applied with nitrogen fertilizer. Averaged over the two soils, biochar amendments increased the production of rice and wheat by 12 % and 17 %, respectively, and these increases can be partly attributed to the increases in soil nitrate retention. Our results demonstrated that although biochar increased the global warming potential at high nitrogen fertilizer application, biochar incorporation significantly decreased N2O emissions while promoting crop production.
  • Authors:
    • Kang, H.
    • Yoo, G.
  • Source: Journal of Environmental Quality
  • Volume: 41
  • Issue: 4
  • Year: 2012
  • Summary: Biochar application to soil has drawn much attention as a strategy to sequester atmospheric carbon in soil ecosystems. The applicability of this strategy as a climate change mitigation option is limited by our understanding of the mechanisms responsible for the observed changes in greenhouse gas emissions from soils, microbial responses, and soil fertility changes. We conducted an 8-wk laboratory incubation using soils from PASTURE (silt loam) and RICE PADDY (silt loam) sites with and without two types of biochar (biochar from swine manure [CHAR-M] and from barley stover [CHAR-B]). Responses to addition of the different biochars varied with the soil source. Addition of CHAR-B did not change CO2 and CH4 evolution from the PASTURE or the RICE PADDY soils, but there was a decrease in N2O emissions from the PASTURE soil. The effects of CHAR-M addition on greenhouse gas emissions were different for the soils. The most substantial change was an increase in N2O emissions from the RICE PADDY soil. This result was attributed to a combination of abundant denitrifiers in this soil and increased net nitrogen mineralization. Soil phosphatase and N-acetylglucosaminidase activity in the CHAR-B-treated soils was enhanced compared with the controls for both soils. Fungal biomass was higher in the CHAR-B-treated RICE PADDY soil. From our results, we suggest CHAR-B to be an appropriate amendment for the PASTURE and RICE PADDY soils because it provides increased nitrogen availability and microbial activity with no net increase in greenhouse gas emissions. Application of CHAR-M to RICE PADDY soils could result in excess nitrogen availability, which may increase N2O emissions and possible NO 3 leaching problems. Thus, this study confirms that the ability of environmentally sound biochar additions to sequester carbon in soils depends on the characteristics of the receiving soil as well as the nature of the biochar.
  • Authors:
    • Daughtry, C. S. T.
    • Vigil, M.
    • Evans, R.
    • Aguilar, J.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 2
  • Year: 2012
  • Summary: Crop residue is important for erosion control, soil water storage, filling gaps in various agroecosystem-based modeling, and sink for atmospheric carbon. The use of remote sensing technology provides a fast, objective, and efficient tool for measuring and managing this resource. The challenge is to distinguish the crop residue from the soil and effectively estimate the residue cover across a variety of landscapes. The objective of this study is to assess a select Landsat Thematic Mapper (TM) and hyperspectral-based indices in estimating crop residue cover and amount for both standing and laid flat, and between two winter wheat ( Triticum aestivum L.) harvest managements (i.e., stripper-header and conventional header) and fallow following proso-millet ( Panicum miliaceum L.) plots. The primary plots were located in Colorado with additional plots in eastern Montana, Oregon, and Washington states. Data collected include hyperspectral scans, crop residue amount (by weight) and residue cover (by photo-grid). Mean analyses, correlation tests, and spectral signature comparison show that the relative position of the crop residues affected the values of some remote sensing indices more than harvest management. Geographical location did not seem to influence the results. There was not enough evidence to support the use of these indices to accurately estimate the amount of residue. Hyperspectral data may deliver better estimates, but in its absence, the use of two or more of these datasets might improve the estimation of residue cover. This information will be useful in guiding analysis of remotely sensed data and in planning data acquisition programs for crop residue, which are essentially nonexistent at present.
  • Authors:
    • Al-Amoud, A. I.
    • Alabdulkader, A. M.
    • Awad, F. S.
  • Source: Agricultural Economics – Czech
  • Volume: 58
  • Issue: 2
  • Year: 2012
  • Summary: A mathematical sector model has been formulated to optimize the cropping pattern in Saudi Arabia aiming at maximizing the net annual return of the agricultural sector in the country and ensuring the efficient allocation of the scarce water resources and arable land among the competing crops. The results showed the potential for Saudi Arabia to optimize its cropping pattern and to generate an estimated net return equivalent to about 2.42 billion US$ per year. The optimized cropping pattern in Saudi Arabia has been coupled with about 53% saving in water use and about 48% reduction in the arable land use compared to the base-year cropping pattern. Comparable weights was given to different crop groups by allocating about 48.4%, 35.4%, 13.1%, and 3.2% to grow cereals, fruits, forages, and vegetables, respectively. These findings are in line with the national strategy to rationalize the cultivation of water-intensive crops in favour of highly water-efficient crops.
  • Authors:
    • Ganesh-Kumar, A.
    • Pullabhotla, H.
    • Gupta, N.
    • Shreedhar, G.
    • Gulati, A.
  • Issue: 1159
  • Year: 2012
  • Summary: This paper reviews the key policies with regard to agriculture inputs such as seed, fertilizer, water, agricultural equipment, research, extension, and agricultural credit. It also provides an overview of the policies and programs related to agricultural output markets that are crucial for improving cereal production in the country. A review of the past performance and policies of India's foodgrain sector reveals that the main drivers of growth have been modern inputs and technology, institutions, and markets with the changing role of the public and private sectors. The present challenge facing Indian policymakers is to efficiently balance food security concerns and higher growth objectives. This will require not only pushing the production frontier to sustainably augment supply, but also ensuring strategic management of foodgrains including procurement and distribution. The review of input policies highlights the pressure placed on foodgrain systems, in a business-as-usual scenario that extensively subsidizes input and promotes their intensive usage. Fallouts such as excessive groundwater withdrawals and distorted application of nitrogenous fertilizers have implications on the environmental sustainability of natural resources apart from being a considerable fiscal burden. The current policy of subsidizing agricultural power, irrigation, and fertilizers has outlived its relevance and is actually constraining agricultural investments in areas where the returns are higher. Although it is difficult to completely remove these subsidies, they still need to be gradually phased out and converted into investments in rural infrastructure (especially roads) and research and extension systems, which desperately need to be (re)vitalized. It is time the government started to actively partner with the private sector (in infrastructure creation and research) and civil society organizations (in extension), as they have played an increasingly important role in recent years. The review of the output management policies show that the current policy paradigm consisting of public procurement of grains at a preannounced minimum support price, public storage, and public distribution has resulted in distortions across crops, especially rice and wheat, as well periodic buildup of large stockpiles and stock rundown of these grains at a high cost to the government. Moreover, public procurement and stocking, coupled with interventionist international trade policies, is often at variance with the trends in international markets, resulting in lost opportunities for Indian exporters of rice and wheat. The regional concentration of the system of public procurement in the northern states, aided by intra-country trade and movement restrictions, has also resulted in large spatial disparity in agricultural productivity and farm income as well as uneven development of output markets across states. As a result, producer and consumer welfare is often compromised, even though the government's objective is to maintain a balance between them. Major reforms on the output side would include linking of MSPs with market prices, allowing futures markets in cereals, liberalizing international trade and bring forth greater competition in domestic trade to ensure output markets are more uniformly developed across states and that the country has a truly integrated market for foodgrains.