• Authors:
    • Arriaga-Sevilla, J.
    • Durán-Zuazo, V. H.
    • García-Tejero, I.
    • Muriel-Fernández, J. L.
  • Source: Agronomy for Sustainable Development
  • Volume: 32
  • Issue: 3
  • Year: 2012
  • Summary: Water shortage is becoming a severe problem in arid and semi-arid regions worldwide, reducing the availability of agricultural land and water resources. Deficit irrigation strategies can improve water-use efficiency and the sustainability of agro-ecosystems, although it is important to model the effects on yield loss due to irrigation water restrictions. This work estimates the water production function in citrus trees, determining the relationship between plant water stress and yield depression, as well as establishing a mathematical model for each phenological stage considered (flowering, fruit growth and ripening), and for the entire productive process. For three consecutive years (2006-2008), four regulated deficit irrigation treatments plus a control (100% crop water evapotranspiration (ET C)) were implemented in 13-year-old citrus trees ( Citrus sinensis L. Osb. cv. Navelina). Different water production functions were determined for each phenological stage, establishing the relationship between the irrigation water stress and crop yield. Our results show that the fruit growth and flowering stages were the most sensitive periods in relation to irrigation water deficit and yield loss. Water stress close to 50% of ET C during the flowering stage would impose a yield loss of up to 20%, whereas this same water stress level during the fruit growth or ripening stages would result in yield losses of nearly 10% and 6%, respectively. The adjustment with cross terms ( r2=0.87) estimated the yield loss with good accuracy, being very similar to data measured in each study season. Consequently, the combined effect of deficit irrigation in different stages would be an additive-multiplicative model, considering that the effect of water stress in previous periods determined the crop yield response. Our model indicated that the crop water production function under deficit irrigation programmes would have a quasi-linear relation for water deficits below to 40% ET C. The previous model functions did not enable us to establish an accurate relationship when the water stress was applied in different phenological stages. Thus, this new interpretation is valuable to improve our knowledge and predict the impact of regulated deficit irrigation and have potential application in precision water stress and sustainable irrigation scheduling for citrus.
  • Authors:
    • Hosseini, S. M. B.
    • Jahansooz, M. R.
    • Heidari, H.
    • Chaichi, M. R.
  • Source: Annals of Biological Research
  • Volume: 3
  • Issue: 6
  • Year: 2012
  • Summary: The aim of the study was to determine the effect of alternate irrigation method and deficit irrigation on radiation use efficiency and forage quality of foxtail millet ( Setaria italica) under a double cropping system after barley ( Hordeum vulgar). Conventional furrow irrigation (M1) and alternate furrow irrigation (M2) methods and different deficit irrigation levels including 100, 85, 70 and 55% of crop water requirement (V1, V2, V3 and V4) were tested in a field experiment on the west of Tehran, Iran for 2 years (2008 and 2009). Results showed that alternate furrow irrigation with 85% of crop water requirement (M2V2) had the highest Absorption Ratio of Photosynthetically Active Radiation (PARAR) and Cumulative Absorption of Photosynthetically Active Radiation (PARCA) in 2008 (P
  • Authors:
    • Liu, S.
    • Jiang, S.
    • Hu, W.
    • Wan, S.
    • Wang, R.
    • Kang, Y.
  • Source: Agricultural Water Management
  • Volume: 109
  • Year: 2012
  • Summary: Due to the mismanagement of water and fertilizer application, cotton cultivation in Xinjiang Northwest China is faced with the problems of soil deterioration and groundwater table ascension. This study was conducted to evaluate the effects of different levels of water applied through drip irrigation on cotton yield and water use in an arid region of Northwest China. The experiment included five water treatments in which the soil matric potential (SMP) at a depth of 20 cm was controlled higher than -10 kPa (S1), -20 kPa (S2), -30 kPa (S3), -40 kPa (S4), and -50 kPa (S5) after cotton was established. The results revealed that the highest cotton evapotranspiration (ETc) was achieved under S1 (-10 kPa) treatment and the ETc, deep percolation and the ratio of deep percolation with irrigation water all increased with increasing SMP threshold. After three years experiment, no salt accumulation in surface soil layer was found under our irrigation schedule. The highest seed cotton yield was obtained when the SMP threshold was controlled above -30 kPa in 2008, and -20 kPa in 2009 and 2010. Moreover, the highest yield obtained after 3 years was 42% higher than the average yield achieved by local farmers in the area. Additionally, the water use value (WUE and IWUE) tended to increase as the SMP threshold decreased in 2009 and 2010. Considering the cotton yield and the impact of irrigation on the underground water table, an SMP higher than -20 kPa at 20 cm can be used as an indicator for cotton drip irrigation scheduling and agronomic practices in this area to help alleviate the dangerous increase in the water table while increasing the cotton seed yield. (C) 2012 Elsevier B.V. All rights reserved.
  • Authors:
    • Jiang, L.
    • Yan, Z. Y.
    • Lai, D. M.
    • Zhang, R. H.
    • Li, Z. G.
    • Tian, C. Y.
  • Source: Ying Yong Sheng Tai Xue Bao
  • Volume: 23
  • Issue: 4
  • Year: 2012
  • Summary: In April-October, 2009, a field experiment was conducted to study the effects of drip irrigation with plastic mulching (MD) on the net primary productivity (NPP), soil heterotrophic respiration (Rh) , and net CO2 exchange flux (NEF(CO2)) of cotton field ecosystem in Xinjiang, taking the traditional flood irrigation with no mulching (NF) as the control. With the increasing time, the NPP, Rh, and NEF(CO2) in treatments MD and NF all presented a trend of increasing first and decreased then. As compared with NF, MD increased the aboveground and belowground biomass and the NPP of cotton, and decreased the Rh. Over the whole growth period, the Rh in treatment MD (214 g C x m(-2)) was smaller than that in treatment NF (317 g C x m(-2)), but the NEF(CO2) in treatment MD (1030 g C x m(-2)) was higher than that in treatment NF (649 g C x m(-2)). Treatment MD could fix the atmospheric CO2 approximately 479 g C x m(-2) higher than treatment NF. Drip irrigation with plastic mulching could promote crop productivity while decreasing soil CO2 emission, being an important agricultural measure for the carbon sequestration and emission reduction of cropland ecosystems in arid area.
  • Authors:
    • Zhang, L. Q.
    • Ma, Z. M.
    • Lian, C. Y.
  • Source: Journal of Triticeae Crops
  • Volume: 32
  • Issue: 1
  • Year: 2012
  • Summary: A field experiment was carried out from March to July, 2007 in Zhangye oasis irrigation region of Gansu province to investigate the effects of a system of bed planting and furrow irrigation on the yield and water use efficiency of beer barley. Under conditions of a bed planting system, grain yield and soil temperature were increased. Compared with conventional flat planting, soil temperature of the 5 cm soil layer in bed planting treatment was raised by 1.27°C and 1.39°C in April and May, respectively. Beer barley plants grew more vigorously in the system of bed planting and furrow irrigation and consumed more water than in conventional flat planting, but the contribution of water to grain yield was greater, and thus bed planting and furrow irrigation showed a significant yield-improving and water saving effect. With the same irrigation quota, 1000-grain-weight increased by 2.10-5.37 g, grains/spike increased by 0.7-7.2, grain yield increased by 480.5-1 983.6 kg/ha and water use efficiency (WUE) was improved by 0.65-4.52 kg/mm/ha in bed planting and furrow irrigation, compared with conventional flat planting.
  • Authors:
    • Zhang, Y. L.
    • Zhang, H. Z.
    • Luo, H. H.
    • Zhang, W. F.
  • Source: Ying Yong Sheng Tai Xue Bao
  • Volume: 23
  • Issue: 2
  • Year: 2012
  • Summary: Taking cotton cultivar Xinluzao 13 as test material, a soil column culture expenment was conducted to study the effects of water storage in deeper (> 60 cm) soil layer on the root growth and its relations with the aboveground growth of the cultivar in arid area with drip irrigation under mulch. Two levels of water storage in 60-120 cm soil layer were installed, i. e., well-watered and no watering, and for each, the moisture content in 0-40 cm soil layer during growth period was controlled at two levels, i.e., 70% and 55% of field capacity. It was observed that the total root mass density of the cultivar and its root length density and root activity in 40-120 cm soil layer had significant positive correlations with the aboveground dry mass. When the moisture content in 0-40 cm soil layer during growth season was controlled at 70% of field capacity, the total root mass density under well-watered and no watering had less difference, but the root length density and root activity in 40-120 cm soil layer under well-watered condition increased, which enhanced the water consumption in deeper soil layer, increased the aboveground dry mass, and finally, led to an increased economic yield and higher water use efficiency. When the moisture content in 0-40 cm soil layer during growth season was controlled at 55% of field capacity and the deeper soil layer was well-watered, the root/shoot ratio and root length density in 40-120 cm soil layer and the root activity in 80-120 cm soil layer were higher, the water consumption in deeper soil layer increased, but it was still failed to adequately compensate for the negative effects of water deficit during growth season on the impaired growth of roots and aboveground parts, leading to a significant decrease in the economic yield, as compared with that at 70% of field capacity. Overall, sufficient water storage in deeper soil layer and a sustained soil moisture level of 65% -75% of field capacity during growth period could promote the downward growth of cotton roots, which was essential for achieving water-saving and high-yielding cultivation of cotton with drip irrigation under mulch.
  • Authors:
    • Li, C. J.
    • Tian, C. Y.
    • Mai, W. X.
  • Source: Australian Journal of Crop Science
  • Volume: 6
  • Issue: 5
  • Year: 2012
  • Summary: Long-term use of drip irrigation technology may lead to root degradation and affect shoot growth and yield. A field experiment was conducted to investigate above- and belowground growth responses to drip irrigation under mulch film (DI) in comparison to flood irrigation under mulch film (FI) in cotton. The monolith method was used to harvest roots at seven timepoints in the growth periods, and the root length, and shoot and root dry weight were measured. The total root length per plant in the 0-10 cm soil layer was higher under DI, whereas in the 30-60 cm soil layer roots were longer under FI. From 65 to 96 days after sowing (DAS), the rate of increase in root length was lower under DI than FI. Total root length decreased after 125 DAS under DI, and was mainly centered in the 0-40 cm soil layer and at distances of 30-70 cm from drip-lines. The shoot:root ratio at 125 DAS was higher under DI than FI, but at 160 DAS the shoot:root ratio abruptly declined under DI. The decline in root length under DI during advanced growth stages may be attributable to the higher root density in shallow soil layers and the increase in the shoot:root ratio. These results suggest that, it are important to increase yield of cotton plants under DI early development of a deep root system and initial control of shoot growth by regulation of water and fertilizer supply.
  • Authors:
    • Kehl, M.
    • Ghergherechi, S.
    • Khormali, F.
    • Ayoubi, S.
  • Source: GEODERMA
  • Volume: 179
  • Year: 2012
  • Summary: In order to contribute to the understanding of carbonate enrichment and clay illuviation in loess-derived soils of subhumid to humid regions, the development of soils was studied along a climate gradient with xeric and udic soil moisture regimes (SMR) and thermic and mesic soil temperature regimes (STR), respectively, in the Golestan Province, Northeastern Iran. Six representative pedons along a climate gradient were investigated. Soils were classified mainly as Hapludalfs and Haploxeralfs. Stability of the geomorphic surface under forest vegetation associated with high leaching conditions has provided appropriate conditions for decalcification followed by clay migration through the profile and formation of argillic horizons in all the studied soils. Clay content of the Bt horizons, soil organic carbon concentration of the A horizons, and depth of the Bk horizons increased significantly with increasing precipitation and decreasing temperature. There was a considerable decrease in silt content with soil development. The main pedofeatures observed in the Bt horizons were clay coatings and decalcified zones. Nodules, coatings and hypocoatings were the main calcitic pedofeatures observed in the Bk horizons. Occurrence and preservation of clay coatings were more pronounced in the udic regions with illite and vermiculite as the dominant clay minerals. Type of clay minerals, shrink/swell properties, and precipitation rate are factors affecting the abundance and preservation of clay coatings. In the strongly developed horizons of the udic SMR, the occurrence of vermiculite clay minerals could reduce the shrink/swell potential and increase the amount of clay coatings. The presence of crystallitic b-fabrics and the high carbonate contents (CaCO3) in the lower horizons (Bk) were mainly related to decalcification processes under descending water flow in the overlying horizons. (C) 2012 Elsevier B.V. All rights reserved.
  • Authors:
    • Stockert, C. M.
    • Muhammad, S.
    • Alsina, M. M.
    • Schellenberg, D. L.
    • Wolff, M. W.
    • Sanden, B. L.
    • Brown, P. H.
    • Smart, D. R.
  • Source: Agriculture Ecosystems and Environment
  • Volume: 155
  • Year: 2012
  • Summary: The optimum yield-scaled global warming potential (GWP) of perennial crops on arid land requires effective strategies for irrigation and fertilization. In 2009-2010, N 2O emissions and CH 4 oxidation were measured from an almond [ Prunus dulcis (Mill.) D.A. Webb] production system irrigated with nitrogen (N) fertilizers. Individual plots were selected within a randomized complete block design with fertilizer treatments of urea ammonium nitrate (UAN) and calcium ammonium nitrate (CAN). Event-related N 2O emissions from irrigation and fertilization were determined for seasonal periods of post-harvest, winter, spring and summer. Peak N 2O emissions in summer occurred within 24 h after fertilization, and were significantly greater from UAN compared to CAN ( p<0.001). Cumulative N 2O emissions from UAN were on average higher than CAN though not significantly different. Air temperature, water-filled pore space (WFPS), soil ammonium (NH 4+) and soil nitrate (NO 3-) showed significant positive correlation with N 2O emissions and significant negative correlation was found for the number of days after fertilization (DAF). The percentage of N 2O loss from N fertilizer inputs was 0.23% for CAN and 0.35% for UAN while CH 4 oxidation offset 6.0-9.3% of N 2O emissions. Total kernel yield was not significantly different between fertilizer treatments. Yield-scaled GWP for almond from CAN (60.9 kg CO 2eq Mg -1) and UAN (91.9 kg CO 2eq Mg -1) represent the first report of this metric for a perennial crop. These results outline effective irrigation and fertilization strategies to optimize yield-scaled GWP for almond on arid land.
  • Authors:
    • Donkoh, S. A.
    • Amikuzino, J.
  • Source: African Crop Science Journal
  • Volume: 20
  • Issue: Suppl. 2
  • Year: 2012
  • Summary: Climate variability, the short-term fluctuations in average weather conditions and agriculture affect each other. Climate variability affects the agroecological and growing conditions of crops and livestock, and is recently believed to be the greatest impediment to the realisation of the first Millennium Development Goal of reducing poverty and food insecurity in arid and semi-arid regions of developing countries. Conversely, agriculture is a major contributor to climate variability and change by emitting greenhouse gases and reducing the agroecology's potential for carbon sequestration. What however, is the empirical evidence of this inter-dependence of climate variability and agriculture in Sub-Sahara Africa? In this paper, we provide some insight into the long run relationship between inter-annual variations in temperature and rainfall, and annual yields of the most important staple food crops in Northern Ghana. Applying pooled panel data of rainfall, temperature and yields of the selected crops from 1976 to 2010 to cointegration and Granger causality models, there is cogent evidence of cointegration between seasonal, total rainfall and crop yields; and causality from rainfall to crop yields in the Sudano-Guinea Savannah and Guinea Savannah zones of Northern Ghana. This suggests that inter-annual yields of the crops have been influenced by the total amounts of rainfall in the planting season. Temperature variability over the study period is however stationary, and is suspected to have minimal effect, if any, on crop yields. Overall, the results confirm the appropriateness of our attempt in modelling long-term relationships between the climate and crop yield variables.