• Authors:
    • Hammond, R.
  • Source: IOBC/WPRS Bulletin
  • Volume: 64
  • Year: 2011
  • Summary: Slugs are often problems in field crops grown using conservation tillage practices in the eastern United States, as well as certain locations in the Midwest and the southern USA, as well as in Canada. Although most concern has been on corn and soybean, reports of problems from dry beans, cotton, oil-seed rape, sunflowers, winter wheat, and fall planted alfalfa are often received. Although most problems are in fields located in the original forested areas of eastern and southern USA, reports are also being received from the Great Plains' grass lands of slug issues in irrigated no-till fields. Overall, slug problems have increased in geographical area as growers in the USA and Canada have adopted conservation tillage practices. As in other areas of the world, determining new methods of slug control is of utmost importance in order to allow growers to continue using conservation tillage practices. In areas that are new to slugs, a primary concern is educating growers on IPM approaches to slug management.
  • Authors:
    • He, Jin
    • Li, HongWen
    • Wang, QingJie
    • Zhang, XiRui
    • Li, Hui
    • Zhang, DongYuan
  • Source: Nongye Jixie Xuebao (Transactions of the Chinese Society of Agricultural Machinery)
  • Volume: 42
  • Issue: 10
  • Year: 2011
  • Summary: According to the problems of few available no-till seeders and residues-blocking and bed-damaging during the seeding of wheat in maize residues cover fields in permanent raised beds (PRB) in northwest oasis farming areas, the new anti-blocking (residue-chopping and throwing by powered L-type hammering blade and residue-cutting by knife type opener) and bed renovation (bed-reshaping by double-wing plough) ideas were put forward. The powered hammering blade no-till wheat seeder for PRB was designed. The key parameters for L-type hammering blade, opener and double-wing plough were determined. The experiment in maize residue cover fields showed that the seeder was effective in solving residues blocking. Compared with 2BMF-5 no-till wheat seeder, the spring wheat yield was similar and bed renovation effect was better with the decreased soil disturbance.
  • Authors:
    • Heddadj, D.
    • Cloarec, M.
  • Source: Options Mediterraneennes. Serie A, Seminaires Mediterraneens
  • Issue: 96
  • Year: 2011
  • Summary: An experimental device has been set up for ten years at the Kerguehennec Experimental Station (Chambre Regionale d'Agriculture de Bretagne) located in Brittany (western France) on the basis of a corn/wheat/rape/wheat rotation. The study, in the western context of France, compares three tillage practices (moldboard plowing, surface tillage and no-tillage) and two nutrient sources (mineral and poultry manure), each management systems repeated three times. The aim of this study was to evaluate the effect of reduced tillage and manure fertilization on the evolution of soil characteristics: porosity, aggregate stability, organic carbon, hydraulic conductivity and earthworm populations. The results show that treatments without plowing know a decline of global porosity on the layer 0-25 cm, particularly in the case of the no-till. Although the abundance and biomass of earthworms are increased in reduced tillage, the decrease of porosity is not compensated. The consequence is the decline of hydraulic conductivity, in the case of the no-till. Surface tillage seems to constitute the best compromise, because it maintains or improves the infiltrability thanks to the improvement of aggregate stability in the surface layer and the protection of soil surface by the presence of a mulch.
  • Authors:
    • Robertson,G. P.
    • Hamilton,S. K.
    • Jasrotia,P.
    • Bhardwaj,A. K.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 140
  • Issue: 3-4
  • Year: 2011
  • Summary: Intensively cropped agricultural production systems should be managed to improve soil quality and ecological processes and ultimately strengthen system capacity for sustained biological productivity. We examined the long-term changes (>20 years) in soil quality and productivity with incorporation of ecological management principles in a set of intensively managed row crop systems of the upper Midwest, USA. Replicated experimental treatments include corn (maize)-soybean-wheat cropping systems under four different management regimes: (a) conventional tillage and fertilizer/chemical inputs ( Conventional), (b) no tillage with conventional fertilizer/chemical inputs ( No-till), (c) conventional tillage with 30% of conventional fertilizer/chemical inputs and a leguminous cover crop ( Reduced Input), and (d) conventional tillage with no fertilizer/chemical input and a leguminous cover crop ( Organic). Effects of these treatments on soils were compared by developing a soil quality index (SQI) from 19 selected soil health indicators. An old field community maintained in early succession provided a benchmark for comparison. Reduction in tillage or fertilizer ( No-till, Reduced Input and Organic) resulted in increased SQI and improved crop production. The No-till (SQI=1.02) and Reduced Input (SQI=1.01) systems outperformed Conventional management (SQI=0.92) in nitrogen availability and use efficiency, soil stability and structure improvement, and microbial nitrogen processing. Improvements in soil quality corresponded with increased primary production and crop yield in these systems, illustrating the value of an ecologically defined SQI for assessing the long-term effects of fertility and tillage management regimes in agricultural production systems.
  • Authors:
    • Nalley, L. L.
    • Popp, M.
  • Source: Journal of Agricultural and Applied Economics
  • Volume: 43
  • Issue: 3
  • Year: 2011
  • Summary: Arkansas cropping pattern changes at the county level were estimated under various scenarios involving a likely decline in water availability, the development of a biomass market for renewable energy production, and the potential of a widely used carbon offset market. These scenarios are analyzed separately and jointly to determine which of the three scenarios is expected to have the largest impact on net (emissions - sequestration) greenhouse gas (GHG) emissions, renewable fuels feedstock supply, and producer net returns. Land use choices included conventional crops of rice, cotton, soybean, corn, grain sorghum, pasture, and hay. Specialty crops of loblolly pine and switchgrass were modeled for their respective potential to sequester carbon and provide feedstock for renewable fuels. GHG emissions were measured across an array of production methods for each crop. Soil and lumber carbon sequestration was based on yield, soil texture, and tillage. Using the concept of additionality in which net GHG emissions reductions compared with a baseline level were rewarded at a carbon price of $15 per ton along with $40 per dry ton of switchgrass, baled at field side, revealed that irrigation restrictions had the largest negative impact on producer net returns while also lowering net GHG emissions. Introducing the higher carbon price led to minor positive income ramifications and greatly reduced net GHG emissions. Biomass production returns were higher than the returns from the carbon offset market, however, at the cost of greater net GHG emissions. The combination of all factors led to a significant increase in switchgrass and pine production. In this scenario, approximately 16% of the total income losses with lower nonirrigated yields were offset with returns from biomass and carbon markets. Lowest statewide net GHG emissions were achieved given least irrigation fuel use and a greater than 15% increase in carbon sequestration with pine and switchgrass.
  • Authors:
    • Moreno, M. F.
    • Diaz, M.
    • Roldan, J.
  • Source: Acta Horticulturae
  • Issue: 889
  • Year: 2011
  • Summary: Irrigation water management in the Genil-Cabra irrigation district, located in the province of Cordoba, southern Spain, was studied using three irrigation performance indicators: relative irrigation supply (RIS); relative water supply (RWS) and relative rainfall supply (RRS). All indicators have been calculated as in a global way as grouping data according to crop type, irrigation method and soil texture. All information of agronomic and hydraulic variables was incorporated in a Geographic Information System (GIS) to ease its management. Results show that applied irrigations are deficit irrigations because RIS values are relatively low. However, RWS values are greater and evaporative demand may be satisfied along crop development cycle. RRS indicator varies less than the other two and, together with RWS, permits to know the evapotranspiration fraction covers by rain water. Irrigation water management in four crops (olive, cotton, sunflower and maize) is considered to be adequate. In the case of sugar beet and asparagus, the deficit is larger. Wheat and garlic are the two crops that show inefficient management due to an excess supply of water. RWS and RIS values are higher for sprinkler irrigation than for drip irrigation. Soil type has little influence on irrigation management. In general, more water is applied to crops planted in sandy loam soils than in silty clay loam soils. The mean values of performance indicators we have calculated are very useful to know farmer's behaviour and the general trend, although the used sample is not significant to characterize the global irrigation district.
  • Authors:
    • Shan, Y.
    • Mu, M.
    • Han, S.
    • Zhang, Y.
    • Yu, K.
  • Source: Zhongguo Shengtai Nongye Xuebao / Chinese Journal of Eco-Agriculture
  • Volume: 19
  • Issue: 4
  • Year: 2011
  • Summary: Yantai (a city in Shandong Province) is a strong base for winter wheat-maize double-copping system. A previous double-copping system experiment involving single-stem late wheat intercropped with late-maturing maize in Longkou (a county of Yantai City) yielded 22 770 kg.hm -2. Other studies have reported grain yields excess of 22 500 kg.hm -2 in North China. For various reasons, however, replicating these experiments at field scales has not been feasible. As one of the first institutions to develop super-high-yield experiments, the Grain and Food Safety Research Center of China Agricultural University was founded in July 2004 in Yantai City, Shandong Province, at where we conducted a 3-year experiment on high-yield technology system of double-cropping system. Based on weather analysis in Longkou and Laizhou Counties of Yantai City, where super-high-yield experiments were first conducted, this paper put forward a new research direction that makes rational use of the abundant light, heat and species resources in Yantai for high-yield wheat-maize double copping system. The strategy delayed the sowing time of wheat to get the effective temperature (≥16degreesC) for maize to fully exploit yield potential of longer growth period maize varieties. Two modes of double-cropping system cultivation techniques with suitable improved varieties were designed and selected. Based on the design, Longkou was best fitted for a double-copping system of mid-late wheat intercropped with mid-late maturing maize with Oct. 10 -> Oct. 10 crop-rotation periods. Laizhou, on the other hand, was best fitted for double-copping system of single-stem late wheat variety mixed with mid-late maturing maize with Oct. 15 -> Oct. 15 crop-rotation periods. Furthermore, the corresponding suitable varieties were incorporated into the experiments. The results of the double-copping system experiments were as follows: Longkou was suitable for the mid-late wheat "Liangxing 99" intercropped the mid-late maturing maize "Jinhai No. 5" of double-copping system with Oct. 10 -> Oct. 10 crop-rotation period. Laizhou was suitable for directly sowed single-stem late wheat "Liangxing 99" mixed with the mid-late maturing maize "Jinhai 607" of double copping with Oct. 15 -> Oct. 15 crop-rotation period. The results of three-year high-yield experiments in Laizhou and Longkou showed that yields were above 21 000 kg.hm -2 per year. Yields for the last year reached the expected target of 22 500 kg.hm -2. Yields for the area of 0.074 hm 2 reached 24 792.45 kg.hm -2 for the two seasons. The study showed that wheat-maize double-cropping system technology that made full use of light, heat and variety resources was more rational for Yantai, which brought local potential productivity to full realization.
  • Authors:
    • Smith, D.
    • Yang, W.
    • Chen, X.
    • Liu, W.
    • Zhang, J.
  • Source: African Journal of Agricultural Research
  • Volume: 6
  • Issue: 27
  • Year: 2011
  • Summary: Production practice shows shaded soybean in wheat-maize-soybean; relay strip intercropping system has better tolerance to drought as compared with sole cropping soybean. Our researches are to understand the reasons through non-hydraulic root signals (nHRS), yield and the relationships among them. Pot experiments were conducted with two soybean cultivars, under shade of maize (LI) and normal irradiance (HI). nHRS were traced during manipulative progressive soil drying period at branching stage under good soil conditions (HW), water stress treatment (LW), in 2010. Well-watered (WW), light drought (LD), moderate drought (MD) and severe drought (SD) were applied in 2009. In response to soil drying, nHRS appeared earlier in Gongxuan No.1 (GX) than Gongqiudou 05-8 (GQ) under two irradiance treatments, but it disappeared earlier for GX than GQ under normal irradiance. GX exhibited a wider average soil water content threshold range (TR) of nHRS under low irradiance. Drought stress significantly decreased the shoot dry mass, root mass and grain yield (P
  • Authors:
    • Adetunji, M.
    • Makinde, E.
    • Akande, M.
  • Source: Communications in Soil Science and Plant Analysis
  • Volume: 42
  • Issue: 9
  • Year: 2011
  • Summary: Field trials were conducted at the Institute of Agricultural Research and Training Ibadan in 2000 and 2001 cropping seasons to evaluate the efficiency of some phosphorus (P) sources, rates, and frequency of application on grain yields of maize and cowpea grown sequentially. The experiment was laid out in a split-split plot arrangement using randomized complete block design, with three replications. The main plot was frequency of fertilizer application (seasonal and annual). Source of P [single superphosphate (SSP: 18% P 2O 5)]; Ogun rock phosphate (OPR: 20.21% P 2O 5), and crystallizer super (CS: 31.4% P 2O 5) constituted the subplots. The P rates (0, 20, 40, and 60 kg P ha -1) were the sub-subplots. An early maize cropping followed by a late-season cowpea was the sequential cropping, while an early maize followed by a late-season maize was the continuous cropping. The croppings were repeated the second year. Frequency of P application and source of P were significantly different while rates of application were not. Maize and cowpea grain yields from the control treatment were significantly less than yields from P-treated plots. Maize grain yields were slightly greater in plots alternated with cowpea, compared to continuous maize. Relative agronomic efficiency (RAE) values of OPR and CS were 67% and 75%, respectively, in annual application and 140% and 134% in seasonal applications, respectively, in 2000. In 2001, the trend was almost similar to 2000 except that there was a decline in RAE values of cowpea. Each Naira invested in the annual application returned about Naira 3.12 while about Naira 2.13 was returned with the seasonal application (Naira 125.00 is the equivalent of USD$1.00). The OPR and CS can serve as alternatives to water-soluble sources such as SSP.
  • Authors:
    • Garcia, F.
    • Garcia, A.
    • Ernst, O.
    • Cano, J.
    • Bordoli, M.
    • Beux, L.
    • Bautes, C.
    • Barbazan, M.
    • Quincke, A.
  • Source: Agrociencia (Montevideo)
  • Volume: 15
  • Issue: 2
  • Year: 2011
  • Summary: The objectives of this study were to summarize the recent information generated in the country related to the potassium fertilization and find a tentative critical level of Potassium (K) in soil for various crops in Uruguay, using the most widely used K soil test. The data come from 50 K-response experiments in barley, wheat, corn, soybeans, sorghum, and sunflower, conducted by different working groups from 2004 to 2010, in soils with different texture and exchangeable K levels. The fertilizer rates ranged from 0 to 240 kg/ha of K 2O and in all cases the source of K was broadcasted KCl at planting date. Potassium fertilizer increased crop yield in 15 of 50 sites (Pr