• 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:
    • Pu, Y. L.
    • Xiao, H. L.
    • Wang, D.
    • Zhang, J. L.
    • Qin, S. H.
  • Source: Acta Agronomica Sinica
  • Volume: 37
  • Issue: 1
  • Year: 2011
  • Summary: Water supply scarcity is the main limiting factor for sustainable agriculture development in semiarid areas on the Western Loess Plateau. Because of imbalance for rainfall distribution, yield and water use efficiency (WUE) of potato, one of the dominant crops in middle Gansu province, are relatively low. To optimize supplemental irrigation system using limited catchment rainfall for rain-fed potato in the area, field experiments were carried out in 2008-2009 to determine evapotranspiration, WUE, yield, yield traits and quality of rain-fed potato under different supplemental irrigation amounts and timings. The results showed that WUE of potato increased significantly in the supplemental irrigation treatment of 45 mm, and decreased with increasing of irrigation amount. WUE and irrigating water use efficiency (IWUE) of potato were higher with supplemental irrigation at the seedling than the tuber expanding stage. WUE and IWUE were the highest under the 45 mm of irrigation at the seedling stage. Yield, rates of bigger tuber and middle tuber in rain-fed potato were increased, and small tuber rates were decreased by supplemental irrigation. Big tuber rates were increased by supplemental irrigation at the seedling stage, while medium tuber rates were increased by supplemental irrigation at the tuber expanding period. Potato numbers per plant were decreased, but tuber yield per plant was increased by supplemental irrigation. With increasing of irrigation amount, the yield of potato was not increased significantly, but green tuber rate and blet tuber rate were increased significantly. Starch content of potato was reduced, while protein content of tuber was increased by supplemental irrigation. Supplemental irrigation of 45 mm at seedling is optimal irrigation system for rain-fed potato in the area.
  • Authors:
    • Yi, L.
    • Xin, R.
    • Min, L.
    • Lijun, G.
    • Man, F.
  • Source: Nongye Jixie Xuebao = Transactions of the Chinese Society for Agricultural Machinery
  • Volume: 42
  • Issue: 3
  • Year: 2011
  • Summary: In order to seek the variations of soil water repellency and its relationship with soil moisture content, soil salt content and pH value, soils samples were collected in two profiles at two grids (intervals were 10 cm * 10 cm and 5 cm * 5 cm, respectively) in a newly cultivated cotton field mulched with plastic film and irrigated with trickle method in Xinjiang. The soil water repellency, soil moisture content, soil salt content and pH value of the profiles were tested and analyzed using the methods of classical statistics, geostatistics and correlation analysis. The results showed that the soil water repellency had moderate variability and the spatial auto-correlation was under the level of the middle class in secondary saline field profiles. The strongest soil water repellency appeared around the depth of 40 cm and the characteristics of soil water repellency were not obvious when the depth was deeper than 80 cm. The soil moisture content and the soil water repellency appeared to be positively related at 0-40 cm depth and negatively related at 40-80 cm depth. Soil salt content and soil water repellency appeared to be positively related to the surface soil layer at 0-10 cm depth but negatively related to the other depth. The pH value and the soil water repellency mostly were generally positively related.
  • Authors:
    • Lehane, K.
    • Orange, D.
    • Holmes, C.
    • King, A.
    • Weston, E.
    • Dalal, R.
    • Thomas, G.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 1
  • Year: 2011
  • Summary: Rainfed grain production in semi-arid, subtropical south-west Queensland in north-east Australia is marginal, because of low and variable rainfall and low soil fertility. Current cropping systems are based around winter cereals, with a summer fallow period essential for storing soil water to reduce risk. Increasing the soil water storage and the efficiency of water and nitrogen use is essential for sustainable crop production in this region. The effects on crop production and economic returns of various crop rotations involving winter crops - wheat ( Triticum aestivum), chickpea ( Cicer arietinum), faba bean ( Vicia faba) and canola ( Brassica napus); summer crops - grain sorghum ( Sorghum bicolor) and mung bean ( Phaseolus mungo); and fertilizer N application to wheat, canola and grain sorghum were studied from 1996 to 2005 on a grey Vertisol. Annual rainfall was above the long-term average in 6 of these 10 years and below average in 4 years. Crops were either not sown or failed due to drought in 3 years during this period. Under the seasonal conditions and grain prices that occurred during this experiment, mean annual gross margin was $100/ha greater for a 2-year chickpea-wheat rotation, $20/ha greater for a faba bean-canola-wheat rotation and $45/ha greater for an alternate cereal-grain legume rotation involving grain sorghum, mung bean, wheat and chickpea than for continuous wheat ($40/ha), where no nitrogen fertilizer was applied to wheat, canola or grain sorghum. Where nitrogen fertilizer was applied to target prime hard grain protein in wheat and maximize yield in canola and grain sorghum, chickpea-wheat ($170/ha) was the only rotation to result in greater gross margin than continuous wheat ($110/ha). Chickpea generally yielded well and resulted in a mean yield increase of 22% in the following wheat crop compared with continuous wheat, where no nitrogen fertilizer was applied in wheat and of 11% where N fertilizer was applied in wheat to target prime hard grain protein. On average, the grain legumes, chickpea and faba bean, provided soil nitrogen benefits of 20 and 40 kg N/ha, respectively, thereby reducing nitrogen fertilizer requirements for following cereal crops and canola. Therefore, the profitability and sustainability of crop production in this semi-arid, subtropical environment can be improved, compared with continuous winter cereal cropping, by appropriate crop rotations and nutrient management.
  • Authors:
    • Kumar, N.
    • Kumar, P.
    • Yadav, S. K.
    • Kumar, M.
  • Source: Environment and Ecology
  • Volume: 29
  • Issue: 3B
  • Year: 2011
  • Summary: A field experiment was conducted during 2001-02 to 2005-06 to assess the nutrients utilization and their translocation to grains in various cropping systems. The soil was sandy loam in texture and medium in soil fertility. Seven cropping systems viz. pearlmillet-wheat, pearlmillet-mustard, soybean-wheat-cowpea (f), sorghum (f)-wheat, pearlmillet-potato-green gram, pearlmillet-field pea-maize (f) and cotton-wheat were grown. In general the total nitrogen (N) uptake was higher with 3 crops in a year as compared to 2 crops in a year. The results revealed that the N uptake was highest in soybean-wheat-cowpea (f) cropping system while phosphorus (P) and potassium (K) uptake were highest in pearlmillet-potato-green gram cropping system. During kharif, the highest per cent translocation of N and P to grains was observed in soybean and K in cotton. The translocation percentage of N and P to grains was highest in wheat in sorghum (f)-wheat, and soybean-wheat-cowpea (f) cropping systems, respectively; and K in potato in rabi.
  • Authors:
    • Perri, E.
    • Ayadi, M.
    • Benincasa, C.
    • Gharsallaoui, M.
    • Khlif, M.
    • Gabsi, S.
  • Source: Scientia Horticulturae
  • Volume: 128
  • Issue: 1
  • Year: 2011
  • Summary: Nowadays, lots of efforts are made in Tunisia for the exploitation of wastewater in agriculture in order to face a very elevated mobilization of resources in water (90%). At Sfax, a Governorate placed in the South of Tunisia, the annual rainfall rarely exceeds 200 mm, so the climate is fairly arid. The significant water deficit can be reduced with the reuse of treated wastewater (TWW). The Sfax wastewater originated from the municipal wastewater treatment plant (WWTP) localized at 5 km in the south of Sfax, Tunisia. This WWTP is an aerated lagoon process receiving industrial wastewaters. Its treatment capacity is 24,000 m 3/day. Part of TWW is sent to the olive crops of El Hajeb, as part of a proposed wastewater use in agriculture. Already the wastewater is used to irrigate olive trees and intercrops such as cotton, oats and sorghum silage (Charfi et al., 1999). The aim of the present work was to determine the impact of the irrigation utilizing wastewater on the quality of the oil. The oils analysed were extracted from olives hand-picked directly from the tree and from olives that have fallen under the trees. Moreover, a study on the olive storage has been made in order to evaluate in which way the collection of the fruit could influence the quality of the oil. The results obtained showed that: - Olive trees benefit from this contribution of water; - irrigation by wastewater has a significant effect in the fatty acid composition; - oils relative to olive trees irrigated with wastewaters are more sensible to the oxidization especially after olive storage; - oils coming from olive trees irrigated with wastewaters are richer in polyphenols; - oils extracted from fallen olives are of poor quality essentially after olives storage and when olive trees are irrigated by wastewater.
  • Authors:
    • Granier, M.
  • Source: Options Mediterraneennes. Serie A, Seminaires Mediterraneens
  • Issue: 96
  • Year: 2011
  • Summary: Continuous use, mostly by mono cultivation of cereal, of agricultural lands leads to soil degradation by tillage erosion, rain and wind - especially in the Mediterranean region - with consequences for the loss of organic matter, the destruction of the field and finally the gradual disappearance of topsoil. The creation of a permanent cover by implantation of a legume pioneer and rational exploitation of this system of crops allows the recovery of the biosphere and the return to productivity of the treated lands. An environmental management of degraded land under a rainfall less than 400 mm sets a positive development in these soils following a cultural practices described and implemented in Tunisia from 2003 to 2009 in the Goubellat region by AAG/SAG.
  • Authors:
    • Nascimento, J. J. V. R. do
    • Oliveira, G. dos S.
    • Silva, G. F. da
    • Pereira, R. G.
    • Paiva, M. R. de F. C.
  • Source: Revista Verde de Agroecologia e Desenvolvimento Sustentavel
  • Volume: 6
  • Issue: 2
  • Year: 2011
  • Summary: The planting of castor bean ( Ricinus communis L.) by seedlings can be an alternative for a better use of the short rainy season in the Brazilian semiarid, but in this region, irrigation water, almost always has a salt concentration that affects the quality of seedlings the vast majority of oil. In this context, this work was to study the effects of saline water at levels of 0.5, 1.5, 2.5, 3.5, 4.5 and 5.5 dS m -1 and two volumes substrate: 1.0 and 2.5 L on the germination and early growth of two castor bean cultivars (BRS BRS Paraguacu and Northeast). The study was conducted in the open at the Experimental Station of Embrapa Cotton, in Barbalha, Ceara. Treatments were arranged in randomized blocks in five replicates, using the factorial 2*2*6. Regardless of cultivar, although the saline water inhibits germination and plant development, the effects were more pronounced in treatments with lower volume of substrate. Both cultivars have suffered more the action of salinity on growth during the initial seed germination.
  • Authors:
    • Koc, D. L.
    • Tekin, S.
    • Kapur, B.
    • Kanber, R.
    • Unlu, M.
  • Source: African Journal of Biotechnology
  • Volume: 10
  • Issue: 12
  • Year: 2011
  • Summary: This study was carried out to determine the crop water stress index (CWSI) for drip irrigated cotton grown on a heavy clay texture soil ( Palexerollic Chromoxerert) under semi-arid climatic condition of East Mediterranean region for three years (2005 to 2007) in Adana, Turkey. Four irrigation treatments designated as full (I 100) with no water stress and slight (DI 70), moderate (DI 50) and strong water stress (continuous stress, dry land) (DI 00) were tested. The treatments of DI 70 and DI 50 received water amount of 70 and 50% of the control treatment and the DI 00 was not irrigated except for germination water given at the beginning of the growing season. Irrigation was initiated when leaf water potential (LWP) reached to -15 bar for full (I 100), -17 bar for DI 70 and -20 bar for DI 50 irrigation treatments. After first irrigation, all the treatments were irrigated at one week interval. The deficit irrigation affected, the irrigation water use, seed cotton yield, dry matter and some yield components such as plant height and number of boll per plant of cotton. Average values of water use, seed cotton yield, dry matter and water use efficiency of full irrigated cotton were 578 mm, 3.28 tha -1, 13.44 tha -1 and 0.59 kgm -3, respectively. CWSI values were calculated from the measurements of canopy temperatures by infrared thermometer (IRT), ambient air temperatures and vapor pressure deficit values for all the irrigated treatments. A non-water stressed baseline (lower baseline) equation for cotton was developed using canopy temperature measured from full irrigated plots as, T c - T a =-1.7543 VPD+1.56; R 2=0.5327 and the non-transpiring baseline (upper baseline) equation was built using canopy temperature data taken from continuous stress plots as, T c - T a =-0.0217 VPD+3.2191. The trends in CWSI values were consistent with the varying soil water content due to the deficit irrigation programs. The relationships between mean CWSI and plant parameters considered in this study were linear except for irrigation water amount. Both dry matter and seed cotton yield decreased with increased soil water deficit. Seed cotton yield (SY) and seasonal mean CWSI values relationship were obtained as, SY=-2.3552 CWSI+3.5657; R 2=0.499. This relationship can be used to predict the seed cotton yield. The results suggest that the cotton crop for this particular climate and soil conditions, should be irrigated when CWSI approaches 0.36. The CWSI approach, according to results of this study, can be accepted as a useful tool to schedule irrigations for cotton.
  • Authors:
    • Kapur, B.
    • Tekin, S.
    • Koc, D. L.
    • Kanber, R.
    • Unlu, M.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 4
  • Year: 2011
  • Summary: A field study on cotton ( Gossypium hirsutum L., cv.) was carried out from 2005 to 2008 in the Cukurova Region, Eastern Mediterranean, Turkey. Treatments were designated as I100 full irrigation; DI 70, DI 50 and DI 00 which received 70, 50, and 0% of the irrigation water amount applied in the I100 treatment. The irrigation water amount to be applied to the plots was calculated using cumulative pan evaporation that occurred during the irrigation intervals. The effect of water deficit or water stress on crop yield and some plant growth parameters such as yield response, water use efficiencies, dry matter yield (DM), leaf area index (LAI) as well as on lint quality components was evaluated. The average seasonal evapotranspiration ranged from 28715 (DI 00) to 58480 mm ( I100). Deficit irrigation significantly affected crop yield and all yield components considered in this study. The average seed cotton yield varied from 1369197 (DI 00) to 3397508 kg ha -1 ( I100). The average water use efficiency (WUE ET) ranged from 6.01.6 ( I100) to 4.80.9 kg ha -1 mm -1 (DI 00), while average irrigation water use efficiency (WUE I) was between 9.43.0 ( I100) and 14.44.8 kg ha -1 mm -1 (DI 50). Deficit irrigation increased the harvest index (HI) values from 0.260.054 ( I100) to 0.320.052 kg kg -1 (DI 50). Yield response factor (Ky) was determined to be 0.98 based on four-year average. Leaf area index (LAI) and dry matter yields (DM) increased with increasing water use. This study demonstrated that the full irrigated treatment ( I100) should be used for semiarid conditions with no water shortage. However, DI 70 treatment needs to be considered as a viable alternative for the development of reduced irrigation strategies in semiarid regions where irrigation water supplies are limited.