• Authors:
    • Shakir, A. S.
    • Rehman, H. U.
    • Sharif, M. B.
    • Hameed, A.
    • Qazi, A. U.
    • Khan, N. M.
    • Afzal, M.
  • Source: Pakistan Journal of Science
  • Volume: 63
  • Issue: 3
  • Year: 2011
  • Summary: Global demands for food & fiber are increasing, necessitating efficient management of the irrigated water. Vast-uncultivated but otherwise fertile lands in Baluchistan, Pakistan attract the authorities to develop the land for agriculture through irrigation. Kachhi plains are one of such areas that will be provided canal water through a gravity canal system off-taking from Indus river at Taunsa Barrage. Efficient use of water especially in arid climates requires good estimates of crop water requirements (CWR). Physical based methods of estimating crop water requirement including the Radiation-Resistance based methods take into account the energy radiated from various sources and the atmospheric resistance depending on air circulation and humidity. This study employs a radiation-resistance based Penman Monteith Equation (Allen et al., 1998) through a spread sheet based tool and CROPWAT software to estimate the crop water requirements in Kachhi Plains, the study area. The study compares the reference crop evapotranspiration with four other well known methods. Meteorological data namely rainfall, temperature, humidity, actual sunshine hours of the closest meteorological station i.e. Jacobabad station is used for the study. Crop coefficients are calculated using FAO guidelines. Total water requirement for Wheat is estimated as 380 mm, while that for Cotton is 928 mm. Crop water requirement calculated by the spreadsheet matches well with that from CROPWAT. The result differs by 3% from the crop water requirements estimated/used by the feasibility report of the Kachhi Canal. Staggering of major crops (wheat, cotton) have been incorporated while computing the CWR. The study can be used for optimization of the cropping pattern and can further be extended by estimation of crop water requirement using lysimeter in the study area. It can also be used to study the impact analysis of meteorological data on the crop water requirement.
  • Authors:
    • Cao, G. D.
    • Xia, J.
    • Zhu, H. W.
    • Tu, J. N.
    • Wang, S. M.
    • Yang, Y.
    • Li, B.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 3
  • Year: 2011
  • Summary: Objective: To study the regularities of the distribution of water, temperature and salinity in drip irrigation cotton field during freeze-thaw season. Method: Based on the data of field survey and laboratory test, this experiment analyzed water, temperature and salinity of each layer of the soil in arid drip irrigation cotton field within the freeze-thaw season. Result: The result showed that the surface soil begins to freeze in late November, and reaches maximum freezing depth in early February, the soil is completely melted in early April. The amplitude of soil temperature is respectively 19.95degreesC and 10.25degreesC at 5 cm and 170 cm depth. In the process of soil freezing, the soil water and salinity show ascendant trend within 0-60 cm depth from November 29th, 2009 to February 11th, 2010. In melting process (February 11th, 2010 April 21th, 2010), the vertical change of soil water and salinity is complicated. Water-salinity vertical distribution have little change within 60-200 cm. The features of temporal variability coefficient of soil water and salinity showed as follow: the variability coefficient of surface soil salinity is greater than bottom during the freeze-thaw period, the change of soil water is greater than soil salinity within 0-80 cm, the temporal variability coefficient of the soil water and salinity have low variability within 80-200 cm. Conclusion: The present study provided useful data for further research on soil water, temperature and salinity distribution during freeze-thaw period, and have certain reference value on soil improvement, agricultural irrigation and other related issues.
  • Authors:
    • Ya, T.
    • Ma, X. W.
    • Ji, H. Y.
    • Li, P.
  • Source: Xinjiang Agricultural Sciences
  • Volume: 48
  • Issue: 7
  • Year: 2011
  • Summary: Objective: This study researched the effects of the optimal proportion of Nitrogen, Phosphorus and Potassium to cotton yield under the same irrigation condition in arid area. Method: The experiment adopted orthogonal saturated designs, design of different N, P fertilization level and their combination treatment, and the total experimental plots were 27. Result: According to the experiment results, the polynomial regression was established, that is, the cotton (ginned cotton) yield (Y) and nitrogen (N) and phosphorus (P) quantity of regression equation: Y=206.58+3.21 XN +9.83 XP -0.003 5 XN2+0.029 XP2-0.011 XNXP . The optimum formulation of fertilizer was: nitrogen fertilizer was 260.74 kg/hm 2; phosphorus fertilizer was 120.07 kg/hm 2. At this time cotton (ginned cotton) can get the highest yield: Y=1 214.98 kg/hm 2. Conclusion: Different levels of nitrogen and phosphorous fertilizers decide different cotton yields. Interaction between Nitrogen and Phosphorus is very significant.
  • Authors:
    • Zhang, F. C.
    • Li, P. L.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 27
  • Issue: 2
  • Year: 2011
  • Summary: To explore the regulation effects of water and nitrogen on cotton population growth and development under the furrow irrigation, a cotton field furrow irrigation experiment was conducted. In the experiments, three kinds of furrow irrigation patterns and three irrigation and nitrogen fertilization levels were designed. The change trends of the cotton population physiological indices were simulated using single peak Gaussian distribution model. The results showed that the model simulation accuracy was relatively high. Compared with the peak values of leaf area duration (LAD) under conventional furrow irrigations (CFI), it decreased by 39.3% under alternative furrow irrigations (AFI) and low nitrogen treatments. Under medium nitrogen treatments, there was no significant difference in all indices. Under high nitrogen treatments, the LAD peak value increased by 17.26%, while the net assimilation rate (NAR) decreased by 21.69%. Meanwhile, under fixed furrow irrigations (FFI) and different nitrogen treatments, the peak value of each indices decreased by 35.1%-44.0%. Compared with the CFI, the LAD peak value decreased by 23.94% under AFI low water treatments. LAD peak value increased by 13.63% and leaf area index (LAI) decreased by 14.2% under AFI medium water treatments. Under AFI high water treatments, there was no significant difference in all indices. Under the FFI and different irrigation treatments, each index decreased by 20.7%-47.22%. Compared with the changes of cotton biomass and yield, the changes of ground dry weight and yield were insignificant under AFI and all water and nitrogen treatments. The FFI ground dry weight decreased by 9.8%-19.3% and the cotton yield decreased by 7.6%-8.9%. The experimental results show that AFI has obvious advantage of regulation effects of water and nitrogen on the performance of cotton population and it can be used to control the population growth and development of cotton effectively. Thus, AFI is recommended in practical applications of cotton water and fertilizer managements.
  • Authors:
    • Wang, Y. M.
    • Mahemujiang, A.
    • Su, L. T.
    • Hudan, T.
    • Mu, H. C.
    • Zhang, J. Z.
  • Source: Transactions of the Chinese Society of Agricultural Engineering
  • Volume: 27
  • Issue: 7
  • Year: 2011
  • Summary: Based on measured date in field, the soil salt changes for cotton field with drip irrigation under the plastic mulch were investigated. Through analyzing the salinity changes in cotton field with different irrigation years in four different growing period, it was concluded that salt content in soil depth 0-20 cm was reduced during before planting, seedling stage, and the boll opening period, but increased during the blooming-boiling stage. Salt content in 40-80 cm increased slowly during before sowing and reduced during the blooming period and boll opening period. The accumulation of salt at emitter was less than that at any other position but more at interspace of films in horizontal direction. The accumulation of salt in 0-20 cm of vertical direction reducted, but in the 60-100 cm it was larger. Meanwhile with the drip irrigation time extension, soil salt content would increase, especially in the 60-100 cm, the increasing trend was significant. At the location of emitter, inter-lines and inter-films, the total salt content would increase successively. The zone of 60-100 cm was of largest salt accumulation. In the cotton growth period, the depth of 0-60 cm soil kept desalting state, and the depth of 60-100 cm soil appeared depositing salt state. The results can provide references for management and prevention of drip irrigation water and salt under mulch in arid regions.
  • Authors:
    • Hachum, A. Y.
    • Farahani, H. J.
    • Oweis, T. Y.
  • Source: Agricultural Water Management
  • Volume: 98
  • Issue: 8
  • Year: 2011
  • Summary: Cotton ( Gossypium hirsutum L.) is the most important industrial and summer cash crop in Syria and many other countries in the arid areas but there are concerns about future production levels, given the high water requirements and the decline in water availability. Most farmers in Syria aim to maximize yield per unit of land regardless of the quantity of water applied. Water losses can be reduced and water productivity (yield per unit of water consumed) improved by applying deficit irrigation, but this requires a better understanding of crop response to various levels of water stress. This paper presents results from a 3-year study (2004-2006) conducted in northern Syria to quantify cotton yield response to different levels of water and fertilizer. The experiment included four irrigation levels and three levels of nitrogen (N) fertilizer under drip irrigation. The overall mean cotton (lint plus seed, or lintseed) yield was 2502 kg ha -1, ranging from 1520 kg ha -1 under 40% irrigation to 3460 kg ha -1 under 100% irrigation. Mean water productivity (WP ET) was 0.36 kg lintseed per m 3 of crop actual evapotranspiration (ET c), ranging from 0.32 kg m -3 under 40% irrigation to 0.39 kg m -3 under the 100% treatment. Results suggest that deficit irrigation does not improve biological water productivity of drip-irrigated cotton. Water and fertilizer levels (especially the former) have significant effects on yield, crop growth and WP ET. Water, but not N level, has a highly significant effect on crop ET c. The study provides production functions relating cotton yield to ET c as well as soil water content at planting. These functions are useful for irrigation optimization and for forecasting the impact of water rationing and drought on regional water budgets and agricultural economies. The WP ET values obtained in this study compare well with those reported from the southwestern USA, Argentina and other developed cotton producing regions. Most importantly, these WP ET values are double the current values in Syria, suggesting that improved irrigation water and system management can improve WP ET, and thus enhance conservation and sustainability in this water-scarce region.
  • Authors:
    • Reyes Serrano, H. F.
    • Alvarez Latorre, P.
    • Poncet, Y.
  • Source: Sécheresse
  • Volume: 22
  • Issue: 4
  • Year: 2011
  • Summary: The Coquimbo region, in Chile, receives a rainfall of 110 mm (annual mean), winter rains, which allow only small scale cereal cropping and pastures for goat and sheep raising. However, thanks to subtle irrigation processes, practiced for centuries, the region used to export high value agricultural products up to mining and transportation workers and facilities settled in the northern arid area of the country. The history of ground occupation and soil uses, throughout the colonial era then in an independent Chile, designed not only the land property modalities, but also the sharing of rights of water usage. During the last sixty years, this system has changed considerably, with both technical causes (artificial lakes to stock water, cheap electric energy in rural areas) and with political and social causes (agrarian reform, agricultural foreign capital). The scientific research program " Suivi de la desertification, connaissance des systemes d'elevage caprin, gestion de la ressource en eau: trois aspects pour la definition d'une politique environnementale incluant la participation des populations dans la IVeregion du Chili ( ECOS-Conicyt)" studied theses changes and their consequences, in order to anticipate consequences and foresee negative ones: the "Limari model" is frequently given as an example of successful economic development and is to be copied in other arid valleys. The irrigation graphic scheme of the valley of Limari is hereafter presented in four dynamic figures, as one of the multidisciplinary supports for research into the well-known problems of geographic and economic balance between rural and urban development, between irrigated and arid areas, and upon the long range effects of the disconnection between land rights and water rights. The new social and economic order will be effected as a consequence of the relationship between new technical applications and new laws and rights. This graphic demonstration is contrived to organise and discuss available information about water, energy, irrigated areas and regulation by law.
  • Authors:
    • Stepannikov, V.
    • Popova, E.
    • Popov, N.
  • Source: Mezhdunarodnyi Sel'skokhozyaistvennyi Zhurnal
  • Issue: 4
  • Year: 2011
  • Summary: Problems associated with the organization and provision of irrigation in the arid regions of Astrakhan Province, Russia, for the efficient use of both water and land are discussed. Recommendations are made for modernizing the structures of irrigated land use on the basis of scientifically based crop rotations. Economic evaluations of the main indicators of irrigated farming efficiency allowed farming systems to be developed for the Province's various natural and climatic zones and according to farm type (for example, meat or dairy farms, and farms devoted to growing cereals, rice, vegetables, cucurbit crops, fodder crops or potatoes).
  • 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:
    • Dhankhar, O. P.
    • Sharma, K. D.
    • Sushil Kumar
    • Kaushik, R. A.
    • Kaushik, N.
  • Source: Indian Journal of Horticulture
  • Volume: 68
  • Issue: 1
  • Year: 2011
  • Summary: The combinations of different tree species namely guava ( Psidium guajava)+ shisham ( Dalberiga sissoo), guava ( Psidium guajava)+ khejri ( Prosopis cineraria), aonla ( Embilica officinalis)+ shisham and aonla+ khejri were planted during Oct. 2000 at a spacing of 6 m * 6 m. After establishment of trees from July 2001 the crop sequences, viz., ridgegourd ( Luffa acutangula)-tomato ( Lycopersicon esculentum), moongbean ( Vigna radiata) - fallow and clusterbean ( Cyamopsis tetragonoloba) - fallow were raised in the interspaces of the trees. Ridgegourd and tomato were raised with drip irrigation (100, 70 and 40% ETc), while moongbean and clusterbean were raised as rainfed crops. In general, maximum plant growth (height and diameter) was recorded under 100% level of irrigation for all the tree species. The tree species showed significant variation in growth. Irrigation treatments varied significantly only for diameter. The yield of intercrops was significantly affected by different irrigation levels and was highest at 100% irrigation level but it was not affected by different tree species. The highest yield of 385, 925, 5300 kg/ha of moongbean, clusterbean and ridgegourd were recorded under guava+ khejri at 100% ETc irrigation level. During rabi season (winter; November-March) maximum yield of tomato (46,220 kg/ha) was observed under 100% ETc. Water use efficiency for trees ranged from 1.19 to 11.0 g/l. Maximum WUE was observed in ridgegourd at all the irrigation levels under different systems.