- Authors:
- Koocheki, A.
- Rostami, L.
- Khorramdel, S.
- Shabahang, J.
- Source: Proceedings of 3rd Iranian Weed Science Congress, Volume 1: Weed biology and ecophysiology, Babolsar, Iran, 17-18 February 2010
- Volume: 1
- Year: 2010
- Summary: In order to investigate the effects of row intercropping wheat ( Triticum aestivum L.) with canola ( Brassica napus L.) on weed populations an experiment was conducted at the Agricultural Research Station of Ferdowsi University of Mashhad during fall growing season in 2009. For this purpose a randomized complete block design with three replications and six treatments was used. The treatments included canola and wheat alone, one row of canola + one row of wheat (1:1), two rows of canola+two rows of wheat (2:2), three rows of canola+three rows of wheat (3:3) and four rows of canola+four rows of wheat (4:4). Weed samplings were done in two stages (early and late of growing season). Then, weeds were counted and measured their dry matter. The results revealed that the highest and lowest amounts of relative frequency were obtained for ryegrass ( Lolium rigidum) and wild spinach ( Chenopodium album) with 2.27-6.82% and 36.36-62.79%, respectively. The maximum and minimum values of weeds dry matter were observed in wheat alone and 4:4, respectively. These findings suggest that intercropping increased diversity and it decreased weed number, density and population.
- Authors:
- Jasso-Chaverria, C.
- Martinez-Gamino, M.
- Source: Proceedings of the 19th World Congress of Soil Science: Soil solutions for a changing world, Brisbane, Australia, 1-6 August 2010. Symposium 3.2.1 Highland agriculture and conservation of soil and water
- Year: 2010
- Summary: Among the main constraints to adopting conservation tillage in the semiarid zones in Mexico's north-central region are: low acceptance among farmers, need of specialized machinery, use of herbicides, and above all, the need to utilize stubble to feed animals. The objective of this study was to assess the effect of different tillage methods in an irrigated corn-oat rotation system on corn grain, stubble, and forage oat yield. Seven tillage methods were evaluated: (1) traditional plow and disk (P+D), (2) disturbing the upper 0-4 in layer (D), (3) without disturbing the upper 0-4 in layer (ND), (4) zero tillage with 0% soil cover (ZT+0%SC), (5) zero tillage with 33% soil cover (ZT+33%SC), (6) zero tillage with 66% soil cover (ZT+66%SC), and (7) zero tillage with 100% soil cover (ZT+100%SC). In each year from 1996 to 2007, corn was sowed on the spring while forage oat was grown during the fall-winter season. Corn grain yield results showed statistical differences among treatments (p≤0.05), where ZT+66%SC was the best treatment, surpassing by 90% the corn yield registered with P+D. The statistical analysis for corn stubble yield showed no differences (p≥0.05) among treatments. With ZT+66%SC, corn stubble production was increased 3.448 ton/ha compared with that of P+D, indicating that farmers can use 2.0 ton ha -1 to cover at least 33% of the soil surface. Forage oat yields within the seven treatments were not statistically different ( P≥0.05), but all ZT treatments were no-till seeded. Our conclusions are that corn and forage oat can be no-till seeded, increasing corn production and keeping stable production of forage oat. These results can be used to provide evidence to farmers of the benefits of adopting conservation tillage.
- Authors:
- Muchaonyerwa, P.
- Chiduza, C.
- Murungu, F. S.
- Source: African Journal of Agricultural Research
- Volume: 5
- Issue: 13
- Year: 2010
- Summary: Production of large biomass yields and weed suppression from cover crops have been major constraints affecting success and uptake of conservation agriculture technologies by smallholder irrigation farmers. A field study was undertaken to evaluate biomass accumulation and N uptake by oats ( Avena sativa), grazing vetch ( Vicia dasycarpa), faba bean ( Vicia faba), forage peas ( Pisum sativum) and Lupin ( Lupinus angustifolius) and their winter weed suppression efficacy in the 2007 and 2008 winter seasons. Cover crops were grown at two fertiliser levels: no fertiliser and fertilized. Control plots were included where no cover crop was grown. At the end of each winter season, glyphosate was applied to kill the cover crops and maize planted. Oats, grazing vetch and forage pea's cover crops produced mean dry weights of 13873, 8945.5 and 11073 kg ha -1 respectively while lupin had the lowest dry weight of 1226 kg ha -1. Oats responded to fertilisation while, there was little or no response from the other cover crops. Oats and grazing vetch also reduced weed density by 90 and 80% respectively while lupin only reduced weed density by 23% compared with the control plots. Grazing vetch fixed a mean of 112 kg N ha -1. The results suggest that legumes such as grazing vetch and forage peas may be grown to maximise biomass yields with minimal fertilizer inputs. Amount of biomass produced was a major factor in controlling winter weeds, while there was a progressive decline in the winter weed burden from the first to the second season. The low C:N ratio of grazing vetch (
- Authors:
- Gill, R. I. S.
- Baljit, S.
- Navneet, K.
- Source: Indian Journal of Agronomy
- Volume: 55
- Issue: 1
- Year: 2010
- Summary: Field experiments were done to standardize the agronomic practices of wheat grown in association with poplar ( Populus deltoides Bartr.) plantation at Ludhiana, Punjab. The study was conducted under block plantation of poplar (Clone G-48) grown at a spacing of 5*4 m, (accommodating 500 trees/ha) at the age of 2, 3 and 4 years in 2004, 2005 and 2006, respectively. The soil of the site was low in available N and medium in available P. Three seed rates (100, 125 and 150 kg/ha) and combinations of 3 N (125, 187.5 and 250 kg N/ha) and 2 P levels (27 and 40.5 kg P/ha) were evaluated to find out the optimum fertilizer and seed requirement of wheat (cv. PBW 343) intercropped with poplar. The height and diameter of trees increased from 10.4-15.1 m and 10.4-16.5 cm, respectively in the span of 2 years (2004-06). Wheat yield under poplar reduced with the increase in tree age. However, the crop under poplar responded positively to higher fertilizer and seed rates. The yield of sole wheat was significantly higher when compared with intercropped wheat. Among 3 seed rates, 25% additional seed rate (125 kg/ha) over recommended to sole wheat significantly increased (6%) the grain yield of wheat under poplar plantation. Among different fertilizer levels, grain yield of wheat was significantly higher (3.93 tonne/ha) at 50% additional N than recommended to sole wheat with recommended P i.e. at 187.5 kg N and 27 kg P/ha. N and P uptake by wheat was higher in sole wheat than under poplar. Additional application of seed and nutrients over the recommended levels significantly increased their uptake. The benefit cost ratio in poplar plantation were highest with the application of 150 kg/ha seed and 187.5+27 kg N+P/ha to wheat.
- Authors:
- Garcia, P. A.
- Benitez, E.
- Ramos, M. E.
- Robles, A. B.
- Source: Applied Soil Ecology
- Volume: 44
- Issue: 1
- Year: 2010
- Summary: Frequent tillage has been widely used in rainfed orchards in SE Spain in order to impede weed establishment and to increase water reposition in the soil profile. However, this practice may lead to soil degradation by decreasing structural stability, organic carbon content and microbial activity. This work examines the effect of different cover crop managements and frequent tillage on soil physical, chemical and biological properties in almond orchards in SE Spain. Two cover crops (oat - Avena sativa L. and oat-vetch - Vicia sativa L.) with two fertilization managements (mineral and organic) and three harvesting regimes (grazing in mid May, hay in early June, and grain-straw in mid July) were compared to a frequently tilled orchard system (three or four tillages per year). Most parameters were sensitive to soil management. Wet aggregate stability, total organic carbon, total nitrogen, carbon:nitrogen ratio, phosphatase, and beta-glucosidase activities increased with cover crops, whereas the soil-water content declined, especially for the grain-straw treatment. The kind of fertilizer affected the available P content, which was higher for mineral fertilizer, and influenced the beta-glucosidase activity, which augmented for the organic fertilizer. Livestock dejections depressed phosphatase activity, and increased WSC and available P. This study suggests that cover crops in semiarid environments improve soil quality compared to frequently tilled management, by increasing the organic matter content, improving the chemical and physical fertility of the soil, and enhancing the soil biological activity. Only higher water extraction by the plants could affect the orchard development and/or productivity; however, early cover crop removal would minimize possible yield losses.
- Authors:
- Biradar, D. P.
- Rathod, P. S.
- Patil, V. C.
- Source: Journal of Medicinal and Aromatic Plant Sciences
- Volume: 32
- Issue: 4
- Year: 2010
- Summary: A field experiment was conducted at Regional Agricultural Research Station, Bijapur on medium deep black soil during rabi seasons of 2004 and 2005 to study the influence of different rabi intercrops on growth and productivity of senna. The treatment consists of five rabi crops (chickpea, safflower, linseed, mustard and wheat) and senna in sole stand as well as intercropping system and safflower+chickpea (2:4) intercropping system as a check. The sole crop of senna recorded significantly better growth and growth parameters as compared to intercropped senna. The leaf and pod yield of senna also followed the same trend as that of growth and growth parameters with different rabi intercrops. Growing of senna with safflower adversely reduced the growth and growth parameters, leaf and pod yield as compared to chickpea, linseed, mustard and wheat.
- Authors:
- Chotte, J.
- Djigal, D.
- Sall, S.
- Pablo, A.
- Saj, S.
- Villenave, C.
- Bonzi, M.
- Source: Biology and Fertility of Soils
- Volume: 46
- Issue: 7
- Year: 2010
- Summary: Soil degradation has led crop yield to decline in many Sahelian countries and is a fundamental agricultural and economical threat for local populations. In Saria, Burkina Faso, long-term experiments are being performed to find efficient soil management practices that could improve soil fertility. A randomized block experiment comprising organic amendment (unamended control, straw at 8.3 t ha -1, manure at 10 t ha -1) coupled with mineral fertilization (no urea, urea at 60 kg ha -1) was started in 1980 with a continuous sorghum ( Sorghum bicolor) cropping system. Twenty-six years after the settlement of the treatments, we compared their effects on nematode populations, community structure, and ecological indices, as well as soil physical and chemical properties at three stages of sorghum's cropping cycle. The addition of manure led to significantly higher soil C, N, and P content and produced a higher sorghum grain yield in comparison to unamended or straw-amended soils. The number of plant-parasitic nematodes (mainly Pratylenchus and Tylenchorhynchus) was significantly higher in plots fertilized with manure in comparison to unamended or straw-amended plots. They were also significantly more abundant when urea was added. Mineral nitrogen fertilization had little impact on free-living nematodes, regardless of S. bicolor development stage, whereas organic amendment significantly raised the abundance of bacterivorous and fungivorous nematodes. Moreover, microphagous nematodes were significantly more numerous in plots amended with straw than with manure. Our results show that, on the long-term, only manure amendment seemed able both to store C and nutrients whereas both manure and straw led to greater microphagous nematode communities.
- 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:
- 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.