• Authors:
    • Barbarick, K. A.
    • Ippolito, J. A.
    • McDaniel, J.
    • Hansen, N. C.
    • Peterson, G. A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 150
  • Year: 2012
  • Summary: Dryland agroecosystems are generally ideal environments for recycling biosolids. However, what is the efficacy of biosolids addition to a no-till dryland management agroecosystem? From 2000 to 2010, we studied application of biosolids from the Littleton/Englewood, CO Wastewater Treatment Plant versus commercial N fertilizer in dryland no-till wheat ( Triticum aestivum, L.)-fallow (WF) and wheat-corn ( Zea mays, L.)-fallow (WCF) rotations at a site approximately 40 km east of Byers, CO. We tested if biosolids would produce the same yields and grain P, Zn, and Ba concentrations as an equivalent rate of N fertilizer, that biosolids-borne P, Zn, and Ba would not migrate below the 10 cm soil depth, and that biosolids application would result in the same quantity of residual NO 3-N as the equivalent N fertilizer rate. Biosolids and N fertilizer produced similar wheat and corn yields; but, biosolids application resulted in smaller wheat grain Ba due to the soil formation of BaSO 4. Biosolids application produced greater NO 3-N concentrations than N fertilizer in the 30-60 and 60-90 cm depths for the WF rotation and all but the 5-10 and 120-150 cm depths for the WCF rotation. We concluded that biosolids application in a no-till managed dryland agroecosystem is an efficacious method of recycling this nutrient source.
  • Authors:
    • Li, Y.
    • Liu, G.
    • Yang, L.
    • Ma, L.
    • Xia, L.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 28
  • Issue: 14
  • Year: 2012
  • Summary: Protective management of arable slope land plays an important role in protection of land resource and aquatic environment in Three Gorges region, China. Base on the regional natural conditions and the utilization of the arable slope land, four tillage modes with H1 (rotation of wheat and maize, wheat intercropped with horse bean, less tillage and ridge cultivation), H2 (rotation of wheat and maize, with Vetiveria ziz anioides contour hedges intercropped at slop length interval of 5 m), H3 (rotation of wheat and maize, with alfalfa contour hedges intercropped at slop length interval of 5 m), H4 (rotation of wheat and maize, conventional management) were conducted from Oct. 2009 to Oct. 2011. The differences of apparent recovery efficiency and Agronomic efficiency of applied nitrogen and phosphorus between treatments were discussed, as well as nitrogen and phosphorus losses through slope land surface runoff were analyzed. The results showed that compared with H4, H1 increased phosphorus use efficiency by 0.06 kg/kg. No significant difference of biological and economic production, apparent recovery efficiency and agronomic efficiency of applied nitrogen and phosphorus was observed among H2, H3 and H4, which showed intercropping with Vetiveria ziz anioides or alfalfa contour hedges wouldn't lead to the reduction of production. Furthermore significant effects on reducing soil erosion and sediment phosphorus loss were observed for H1, H2 and H3. Compared with H4, and sediment losses for H1, H2 and H3 decreased by 48.46%, 52.26% and 58.59% respectively, and sediment phosphorus losses decreased by 30.58%, 47.70% and 44.58% respectively.
  • Authors:
    • Bejiga, G.
    • Khalil, Y.
    • Kumar, S.
    • Haddad, A.
    • Piggin, C.
    • Ahmed, S.
  • Source: Soil & Tillage Research
  • Volume: 121
  • Year: 2012
  • Summary: Conservation agriculture is becoming popular due to its potential for enhanced productivity and cost savings among small scale farmers in developing countries. The International Center for Agricultural Research in Dry Areas is promoting conservation cropping systems that involve cereal-legume rotation in West Asia and North Africa region. Studies were made on the impact of long-term rotation trial on diseases of chickpea and lentil as well as the evaluations of lentil genotypes for their reactions to Fusarium wilt and downy mildew under two tillage practices. In the long-term rotation trials, the two season results showed no significant differences between tillage practices, crops and planting dates and their interactions in affecting mean percent cyst nematode disease. The mean cyst nematode disease incidence ranged from 7.3% on early planted lentil on CT to 14.5% in late planted chickpea on ZT. Tillage practices significantly ( P≤0.05) affected Ascochyta blight incidence but not its severity. The incidence ranged from 4% to 22.5% under early planted chickpea on both tillage practices. Moreover, the mean severity ranged from 3.2 to 5.5 rating in early planted CT and ZT, respectively. The combined analysis showed significant differences ( P≤0.05) among genotypes but not their interactions with tillage for Fusarium wilt and downy mildew reactions. All the genotypes showed less than 10% Fusarium wilt mortality indicating high levels of resistance. The mean downy mildew severity ranged from 1.3 in ILL-7991 to 2.6 rating in ILL6994. This study showed that both soil borne and foliar diseases could be a problem in conservation cropping system and continuous monitoring of diseases is essential to prioritize management practices in relation to conservation agriculture in Mediterranean type environments. Moreover, cool-season legume genotypes with disease resistance and high yield can be developed under conservation agriculture that could also serve traditionally tilled production systems.
  • Authors:
    • Albuquerque, J.
    • Picolla, C.
    • Mafra, A.
    • Andrade, A.
    • Bertol, I.
  • Source: Ciencia Rural
  • Volume: 42
  • Issue: 5
  • Year: 2012
  • Summary: Suitable soil management is one of the bases for sustainability in agricultural systems. The study aimed to evaluate chemical properties of a Humic Dystrudept for 12 years under two tillage systems, with crops rotation and succession. The experiment was carried out in Lages, SC, under conventional tillage (CT) and no-till (NT), with rotation (r) and succession (s) cropping systems, using crop sequences of beans-fallow-maize-fallow-soybean in CTr; maize-fallow in CTs; beans-oats-maize-fodder radish-soybean-vetch in NTr; and maize-vetch in NTs. The experimental design was completely randomized with four replicates. The soil samples were collected in the layers 0-2.5, 2.5-5, 5-10 and 10-20 cm. The variables assessed were total organic carbon (TOC), calcium, magnesium, exchangeable aluminum, phosphorus, potassium, total nitrogen (TN) and water pH. The no-tillage system increased TOC and nutrient levels in comparison with conventional tillage, especially in the surface soil layer. Maize and vetch crop succession had higher TOC and TN contents in the surface soil layer compared to crop rotation under no-tillage.
  • Authors:
    • Kristoffersen, A.
    • Loes, A.
    • Clasen, P.
    • Torp, M.
    • Bernhoft, A.
  • Source: Food Additives and Contaminants Part A-Chemistry Analysis Control Exposure & Risk Assessment
  • Volume: 29
  • Issue: 7
  • Year: 2012
  • Summary: A total of 602 samples of organically and conventionally grown barley, oats and wheat was collected at grain harvest during 2002-2004 in Norway. Organic and conventional samples were comparable pairs regarding cereal species, growing site and harvest time, and were analysed for Fusarium mould and mycotoxins. Agronomic and climatic factors explained 10-30% of the variation in Fusarium species and mycotoxins. Significantly lower Fusarium infestation and concentrations of important mycotoxins were found in the organic cereals. The mycotoxins deoxynivalenol (DON) and HT-2 toxin (HT-2) constitute the main risk for human and animal health in Norwegian cereals. The impacts of various agronomic and climatic factors on DON and HT-2 as well as on their main producers F. graminearum and F. langsethiae and on total Fusarium were tested by multivariate statistics. Crop rotation with non-cereals was found to reduce all investigated characteristics significantly - mycotoxin concentrations as well as various Fusarium infestations. No use of mineral fertilisers and herbicides was also found to decrease F. graminearum, whereas lodged fields increased the occurrence of this species. No use of herbicides was also found to decrease F. langsethiae, but for this species the occurrence was lower in lodged fields. Total Fusarium infestation was decreased with no use of fungicides or mineral fertilisers, and with crop rotation, as well as by using herbicides and increased by lodged fields. Clay and to some extent silty soils seemed to reduce F. graminearum in comparison with sandy soils. Concerning climate factors, low temperature before grain harvest was found to increase DON; and high air humidity before harvest to increase HT-2. F. graminearum was negatively correlated with precipitation in July but correlated with air humidity before harvest. F. langsethiae was correlated with temperature in July. Total Fusarium increased with increasing precipitation in July. Organic cereal farmers have fewer cereal intense rotations than conventional farmers. Further, organic farmers do not apply mineral fertiliser or pesticides (fungicides, herbicides or insecticides), and have less problem with lodged fields. The study showed that these agronomic factors were related to the infestation of Fusarium species and the concentration of mycotoxins. Hence, it is reasonable to conclude that farming system (organic versus conventional) impacts Fusarium infestation, and that organic management tends to reduce Fusarium and mycotoxins. However, Fusarium infestation and mycotoxin concentrations may be influenced by a range of factors not studied here, such as local topography and more local climate, as well as cereal species and variety.
  • Authors:
    • Fetere, V.
  • Source: Zinatniski praktiskas konference, "Zinatne Latvijas Lauksaimniecibas Nakotnei: Partika, Lopbariba, Skiedra un Energija", Jelgava, Latvia, 23-24 February 2012
  • Year: 2012
  • Summary: The aim of studies was to define the impact of pre-sown crop winter rye and buckwheat on the plant growth, yield and grain quality of spring cereals. During research there were evaluated the traits characterizing the yield and grain quality of wheat 'Uffo' and barley 'Rasa'. The soil of biological crop rotation within the period of two years on average was processed with 20.1 t ha -1 of buckwheat green manure or 5.4 t ha -1 buckwheat dry matter and 4.2 t ha -1 rye straws or 2.5 t ha -1 dry matter of rye straws. According to the chemical analysis, the buckwheat dry matter contained nitrogen and phosphorus, which was three times higher than dry matter of rye straws, potassium and calcium was two times higher, but magnesium - five times higher than dry matter of rye straws. Spring wheat 'Uffo' (4.36 t ha -1) and spring barley 'Rasa' (3.23 t ha -1) provided significantly (p
  • Authors:
    • Schlegel, A.
    • Halvorson, A.
  • Source: Agronomy Journal
  • Volume: 104
  • Issue: 5
  • Year: 2012
  • Summary: Limited irrigation management practices are being used in the Central Great Plains to conserve water by optimizing crop water use efficiency. Limited irrigation may reduce total crop biomass production and amount of crop residue returned to the soil. Crop residue production within four no-till (NT) crop rotations [continuous corn ( Zea mays L.) (CC); corn-winter wheat ( Triticum aestivum L.) (CW); corn-winter wheat-grain sorghum ( Sorghum bicolor L. Moench) (CWS); corn-winter wheat-grain sorghum-soybean [ Glycine max (L.) Merr.] (CWSSb)] was measured and changes in soil organic carbon (SOC) and total soil nitrogen (TSN) stocks were monitored for 10 yr. Crop residue yields varied with crop being produced and with rotation, as did residue N and C returned to the soil. The C/N ratio of the residue varied with crop. The SOC and TSN pools increased with time in all rotations. The rate of gain in SOC and TSN mass for each rotation was 717, 477, 335, and 270 kg SOC ha -1 yr -1 and 114, 92, 87, and 84 kg TSN ha -1 yr -1 for the CC, CW, CWS, and CWSSb rotations, respectively, in the 0- to 30.5-cm soil depth. The rate of change in SOC and TSN mass was lowest with CWSSb (8.7 Mg residue ha -1 yr -1) and highest with CC (12.0 Mg residue ha -1 yr -1). Approximately 6.8 to 7.6 Mg residue ha -1 yr -1 would be needed to maintain SOC stocks under limited irrigation.
  • Authors:
    • Muni, R.
    • Saudan, S.
    • Aparbal, S.
    • Man, S.
  • Source: Archives of Agronomy and Soil Science
  • Volume: 58
  • Issue: 4
  • Year: 2012
  • Summary: The objective of the study was to determine the profitability and employment-generation potential of different cropping systems involving menthol mint ( Mentha arvensis L.) as a component of sequential/intercropping in comparison with the most common paddy-wheat-green gram cropping system. Field experiments were conducted at Lucknow, India (26°5′N, 80°5′E and 120 m above mean sea level) for three years from July 2004 to June 2007. Menthol mint yielded the maximum fresh shoot biomass and essential oil (21.0 t and 151 kg ha -1, respectively) grown after sweet basil ( Ocimum basillicum)-potato followed by paddy-potato-menthol mint (18.9 t and 136 kg ha -1, respectively) and maize-mustard-menthol mint (17.7 t and 131 kg ha -1, respectively). Net returns of all the menthol-mint-based cropping systems were 82.6-354% higher than traditional paddy-wheat-green gram cropping system. Maize-garlic-menthol mint+okra was found to be most profitable (77,200 Rs ha -1) followed by pigeon pea+sweet basil-menthol mint+okra (76,120 Rs ha -1). Employment-generation efficiency was much higher in cropping systems involving menthol mint and vegetable crops, the highest (2.21 man days ha -1 day -1) being in a maize-cauliflower-onion-menthol mint+okra cropping system.
  • Authors:
    • Chimbizi, A.
    • Chimphero, L.
    • Mwale, C.
    • Mhango, W.
    • Kambauwa, G.
    • Kabambe, V.
    • Ngwira, A.
    • Mapfumo, P.
  • Source: African Journal of Agricultural Research
  • Volume: 7
  • Issue: 6
  • Year: 2012
  • Summary: Maize ( Zea mays L.) is a major staple food in Malawi. However, low soil fertility resulting from low and inappropriate use of fertilizer practices, continuous monocropping and inappropriate crop residues management coupled with limited resources and droughts keep yields low. This had led to a quest for sustainable solutions such as maize-legume intercropping or rotation including more efficient use of crop residues in smallholder farming systems. Innovation platforms (IP) built around learning centres (LC) located on smallholder farmers' fields in target locations were used as an approach to disseminate integrated soil fertility management (ISFM) technologies and build capacity of farmers, extension staff and other stakeholders. Rotating maize with either groundnut or groundnut intercropped with pigeonpea increased maize grain yield (3678 and 3071 kg ha -1 respectively) compared to sole maize (2260 kg ha -1). These preliminary findings were linked to farmer assessment of technologies where farmers participating in the LCs expressed strong interest in the maize legume rotation technologies. Associated farmer field days outlined constraints underlying technology choice, information that is not usually considered in conjunction with on-farm experimentation. Although, the legumes were highly productive, farmers expressed worries about legume seed availability, disease incidences, weeds infestations and livestock damage. Participating farmers commonly manage residues by burning. Promotion and experimentation with more efficient use of legume residues have shown short-term positive impacts in efforts to promote scaling-out of best fit legume technologies. This study reports the value of multi-stakeholder partnering in scaling-out and evaluation of best fit legume technologies and adoption constraints.
  • Authors:
    • McKone, T. E.
    • Horvath, A.
    • Santero, N. J.
    • Masanet, E.
    • Lobscheid, A. B.
    • Strogen, B.
    • Mishra, U.
    • Nazaroff, W. W.
    • Scown, C. D.
  • Source: Environmental Research Letters
  • Volume: 7
  • Issue: 1
  • Year: 2012
  • Summary: The Energy Independence and Security Act of 2007 set an annual US national production goal of 39.7 billion 1 of cellulosic ethanol by 2020. This paper explores the possibility of meeting that target by growing and processing Miscanthus x giganteus. We define and assess six production scenarios in which active cropland and/or Conservation Reserve Program land are used to grow to Miscanthus. The crop and biorefinery locations are chosen with consideration of economic, land-use, water management and greenhouse gas (GHG) emissions reduction objectives. Using lifecycle assessment, the net GHG footprint of each scenario is evaluated, providing insight into the climate costs and benefits associated with each scenario's objectives. Assuming that indirect land-use change is successfully minimized or mitigated, the results suggest two major drivers for overall GHG impact of cellulosic ethanol from Miscanthus: (a) net soil carbon sequestration or emissions during Miscanthus cultivation and (b) GHG offset credits for electricity exported by biorefineries to the grid. Without these factors, the GHG intensity of bioethanol from Miscanthus is calculated to be 11-13 g CO2-equivalent per MJ of fuel, which is 80-90% lower than gasoline. Including soil carbon sequestration and the power-offset credit results in net GHG sequestration up to 26 g CO2-equivalent per MJ of fuel.