• Authors:
    • Lezaún, J. A.
    • Lacasta, C.
    • Ciria, P.
    • Aibar, J.
    • Pardo, G.
    • Zaragoza, C.
  • Source: Chilean Journal of Agricultural Research
  • Volume: 71
  • Issue: 2
  • Year: 2011
  • Summary: Under semiarid conditions the response of cereal crops to chemical fertilizers and weed control practices with herbicides is often reduced. In fact, the economic profitability of agricultural production in many dryland regions is critically affected by high costs of inputs and low crop yields. As a solution, cropping systems like organic farming, obtaining similar yields and promoting environmental sustainability by reducing fertilizer and herbicides, could be an alternative to conventional systems. In this study, 23 trials were performed in five semiarid regions of Spain during 5 yr to compare different fertilizers and weed control methods on durum wheat ( Triticum durum Desf.) and barley ( Hordeum vulgare L.) yields. The following rotation pattern was developed on the experimental plots: fallow-barley-ground ploughed vetch ( Vicia sativa L.)-durum wheat. Plots either received organic fertilizer, chemical fertilizer, or no fertilizer. In addition, three levels of weed control were applied in cereal plots: flex-tine harrow tillage, conventional herbicide, and no weeding. The results indicated that neither the fertilization nor the weed control have effect on the yield crop.
  • Authors:
    • Irshad, M
    • Ahmad, R
  • Source: Soil & Environment
  • Volume: 30
  • Issue: 1
  • Year: 2011
  • Summary: Boron (B), one of the essential micronutrients, plays vital role in plant growth. Thirty one field experiments were conducted to evaluate the response of wheat, rice and cotton to B application throughout Pakistan during 2005-08. Boron was applied at 1 kg ha -1 as Borax decahydrate (11.3% B) at different times along with recommended doses of N, P and K. The results revealed that B application at sowing time to wheat increased significantly the number of tillers plant -1 (15%), number of grains spike -1 (11%), 1000-grain weight (7%) and grain yield (10%) over control. Among the treatments, B application at sowing time showed best results followed by B application at 1st irrigation and at booting stage. In rice (coarse), B application before transplanting substantially increased number of tillers hill -1 (21%), plant height (3%), panicle length (10%), and number of paddy grains panicle -1 (17%), 1000-grain weight (11%) and paddy yield (31%) over control. Response of fine rice to B application was similar for all yield parameters as in coarse rice. In cotton, B application considerably increased plant height (3%), number of mature bolls plant -1 (12%), seed weight boll -1 (8%) and seed cotton yield (9%) over control. Although, B application at all stages significantly increased yield parameters tested but B application at sowing time was best among all treatments.
  • 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:
    • Lenssen, A. W.
    • Sainju, U. M.
  • Source: Soil Science Society of America Journal
  • Volume: 75
  • Issue: 2
  • Year: 2011
  • Summary: Forages grown in rotation with or without cereals to sustain dryland soil water content and crop production may influence N dynamics. We evaluated the effect of alfalfa ( Medicago sativa L.) and durum ( Triticum turgidum L.)-annual forage cropping sequences on above-(stems+leaves) and belowground (roots) biomass N, dryland soil total N (STN), particulate organic N (PON), microbial biomass N (MBN), potential N mineralization (PNM), NH 4-N, and NO 3-N contents at the 0- to 120-cm depth in northeastern Montana from 2002 to 2005. Cropping sequences were continuous alfalfa (CA), durum-barley ( Hordeum vulgare L.) hay (D-B), durum-foxtail millet ( Setaria italica L.) hay (D-M), durum-Austrian winter pea ( Pisum sativum L.)/barley mixture hay (D-P/B), and durum-fallow (D-F). From 2002 to 2005, total above- and belowground biomass N was 20 to 97 kg N ha -1 greater under CA than other treatments. In 2005, STN, PON, and PNM were 7 to 490 kg N ha -1 greater under CA than D-M, D-B, and D-P/B at 0 to 30 cm but varied by treatment at other depths. In contrast, MBN at 0 to 15 cm and NH 4-N content at 30 to 90 cm were 23 to 37 kg N ha -1 greater under D-B than D-M and D-F. The NO 3-N content at 0 to 120 cm was 65 to 107 kg N ha -1 greater under D-P/B than other treatments. Even though haying removed a greater amount of N, alfalfa increased surface soil N storage and mineralization and reduced the potential for N leaching compared with durum-annual forages, probably due to increased root growth or N 2 fixation. Durum-pea/barley hay, however, increased N mineralization and availability in subsoil layers, probably due to greater root N concentration or downward movement of water-soluble N.
  • Authors:
    • Tang, L.
    • Zheng, Y.
    • Ren, J.
    • Wang, Y.
  • Source: Journal of Yunnan Agricultural University
  • Volume: 26
  • Issue: 6
  • Year: 2011
  • Summary: Through field experiment, we studied the dynamics change of phosphorus in rhizosphere and bulk soil under wheat and faba bean intercropping and wheat monoculture, and the effects rhizosphere and bulk soil phosphorus under wheat and faba bean intercropping and wheat monoculture. The results showed that there was consistency in each growth date of rhizosphere soil phosphorus under wheat intercropping and monoculture, the bulk soil phosphorus content was highest in filling under wheat monoculture, and reached the highest in tilling under wheat intercropping. In wheat and faba bean intercropping, the rhizosphere soil phosphorus content of wheat was increasing from tilling stage to filling stage, and the rhizosphere and bulk soil phosphorus content in maturity was dramatically bringing down. The rhizosphere soil phosphorus contents of wheat increased by 6.81%, 8.71% and 12.95% in jointing, tilling and filling stages, respectively, and reduced by 21.11% in maturity stage.
  • Authors:
    • Yang, L.
    • Yin, S.
    • Xia, L.
    • Yu, Y.
    • Wu, D.
  • Source: PEDOSPHERE
  • Volume: 21
  • Issue: 6
  • Year: 2011
  • Summary: In the Three Gorges Area of China, soil erosion and the resultant non-point source pollution and ecological degradation have endangered agricultural ecosystems and fresh water reservoirs. Although efforts have been undertaken to reduce soil and water losses from slope land used for citrus production, information on the effects of management practices on soil fertility indices is either limited or nonexistent. This study was conducted to compare the effects of 10 years of various management practices, citrus intercropped with white clover (WC), citrus mulched with straw (SM), citrus intercropped with contour hedgerows (CH), citrus orchard land with impermeable membrane (IM), and citrus intercropped with wheat ( Triticum aestivum) and peanut ( Arachris hypogaea) (WP), as treatments on soil fertility indices with that of the conventional citrus management (CM). Results showed that the soil organic carbon, total and available nitrogen, available potassium, and water-stable aggregate (>0.25 mm) contents at the 0-5 cm depth were higher for the WC and SM treatments than the CM treatment. There was also spatial variation in soil fertility along slopes of the WC and SM treatments. The soil total and available nitrogen, phosphorus, and potassium, and water-stable aggregate (>0.25 mm) contents at both the 0-5 and 5-20 cm depths were higher for the CH and IM treatments than the CM treatment. The average soil available nitrogen and available potassium contents were higher for the WP treatment than the CM treatment, but the WP treatment had little effect on the soil organic carbon, total nitrogen, and water-stable aggregate (>0.25 mm) contents. These suggested that white clover intercropping and straw mulching were the most effective approaches to improve soil fertility in citrus orchard land of the Three Gorges area.
  • Authors:
    • Yahuza, I.
  • Source: International Journal of Biosciences (IJB)
  • Volume: 1
  • Issue: 5
  • Year: 2011
  • Summary: Intercropping (growing two or more crops together simultaneously) is increasing being adopted worldwide, probably because there have been suggestions that the system is beneficial in terms of land use efficiency compared to sole cropping. There are several indices for estimating intercrop performance compared to the component sole crops, but as reviewed in this paper, the land equivalent ratio (LER) is the most widely adopted. Yet the LER is constrained because it is not able to account for the relative duration each component in the intercrop spent in the field may have had on intercropping performance. Area time equivalency ratio (ATER) appears to have solved this problem well. However, neither ATER nor LER can account for the physiological or physical basis for the intercropping performance. The crop performance ratio (CPR) is more appropriate in this regard, even though CPR 'adjusted for time', (CPRT) is more efficient where the component crops differ in growth duration. In addition, particularly for intercrops with commercial value, there may be a need to compute a monetary advantage (MA) for intercropping. This paper concludes that in addition to the LER, for certain intercrops such as wheat/faba bean system that has not been widely adopted, there may be a need to use other indices such as ATER, CPR, CPRT and MA as may be applicable in order to understand more fully the nature of intercrop benefits that may exist. Indeed such type of information may help to attract potential growers.
  • Authors:
    • Xu, L.
    • Zhang, P.
    • Guo, W.
    • Liu, R.
    • Yang, C.
  • Source: Jiangsu Journal of Agricultural Sciences
  • Volume: 27
  • Issue: 5
  • Year: 2011
  • Summary: To investigate the effect of wheat-cotton double cropping system on cotton, planting pattern experiments in field were conducted in 2009-2010, with wheat-cotton intercropping system as control. The indexes of development characteristics and yield component of cotton were analyzed. The results were showed as follows. In wheat-cotton intercropping treatment, the development process was earlier, and the forming of fruit node and boll was longer and more than those of cotton transplanted after wheat harvest. The later autumn boll percent was only 3.2%-4.7% and the rate of blossom before frost was 88.6%-95.7%. The cotton in intercropping system also had high biomass and harmonious relationship between vegetative growth and reproduction. For cotton transplanted after wheat harvest treatments, the dry matters were low and pre-summer bolls were few. For cotton with substrate or nutrition treatment, the forming of fruit node and boll was later and less than those of cotton with intercropping treatment, the late autumn boll percents were 11.8%-20.8%, and the rate of blossom before frost was 77.2%-90.7%. The seed yield of cotton with substrate treatment was lower than that of cotton with intercropping treatment, but higher than that of cotton with nutrition treatment. For direct seeding cotton of medium-matured variety after wheat harvest, the reproductive growth was later and weaker. The forming of fruit node and boll was later and had no obvious peak, which easily caused invalid growth at later stage. The late autumn boll percent was 24.5%-34.0% and the rate of blossom before frost and seed yield were low. For direct seeding cotton of early-matured variety after wheat harvest, the transforming growth from vegetative to reproductive growth was earlier. The forming of fruit node and boll was concentrated with higher peak value and the total dry matter in reproductive organ was higher. The late autumn boll percent was only 3.3% and the rate of blossom before frost was 88.0%. The seed yield was equal to that of cotton transplanted after wheat harvest. As a result, the yield of cotton in intercropping system was higher and more stable, and that of transplanted cotton might be potential, while that of direct seedling cotton depended on the variety characteristics.
  • 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