Equity of water distribution along secondary canals in Punjab,Pakistan

Equity in the distribution of irrigation water has long been an operational objective for the management of the large canal systems in the north and west of the Indian subcontinent. How well that operational objective continues to be met is the central concern of the research reported in this paper. Detailed studies of canal operations were conducted on three distributaries in the Lower Chenab Canal system in Punjab Province, Pakistan. Mananwala and Lagar Distributaries off-take in the head reach of the Gugera Branch Canal and Pir Mahal Distributary is at the very tail of this Branch. Flow conditions for these distributaries and of selected outlets served by each were measured daily throughout 1988, and data were converted to discharges. These field observations show that discharge variation at the head of distributaries greatly exceeds the original design criteria. The data also indicate that two design assumptions for outlets are no longer valid: continuous full supply water level in the distributary and outlet modular flow conditions. Field measurements confirm that the distribution of surface water among the outlets of all three distributaries is substantially inequitable. Outlets in the channels' head reaches commonly draw 3 to 6 times greater share of total supplies than do tail outlets. Although all three selected distributaries are perennial canals, some outlets remained dry for up to 90% of the total operational days in a year. Finally, evaluation of field data also shows that better operational procedures at the distributary level can substantially improve water supply conditions in the tail reaches.     

巴基斯坦种子管理研究

结合国外有关研究,梳理了巴基斯坦种子管理体系的有关规定,并提出了今后开展对巴基斯坦种业合作的建议。     

Effect of ascorbic acid on seed germination of three halophytic grass species under saline conditions

Grasses on the Pakistani coast are moderately to highly salt tolerant and have potential for utilization as a cash crop. This study was designed to determine whether seed germination of three halophytic grasses (Phragmites karka, Dichanthium annulatum and Eragrostis ciliaris) could be improved by exogenous application of ascorbic acid (AsA) under saline conditions. Seeds of P. karka were germinated in varying concentrations of NaCl and AsA under different temperature regimes, and seeds of Dichanthium annulatum and Eragrostis ciliaris were germinated at optimal temperatures only. In P. karka, concentrations of AsA (5 and 10 mM) alleviated the salinity effects better at cooler and moderate thermo‐periods, whereas higher concentrations (20 mM of AsA) failed to improve germination under all temperature regimes. AsA was ineffective at a warmer thermo‐period (25/35°C). The rate of germination also increased at all thermo‐periods with the application of AsA except at 25/35°C under saline conditions. Application of AsA improved the germination of E. ciliaris seeds under saline conditions but was inhibitory for D. annulatum in comparison with the untreated control. The rate of germination followed the similar pattern as that of seed germination. Results indicate that AsA has the ability to partially alleviate the effect of salinity on seed germination of some grass species under optimal temperature regime.     

Bovine fasciolosis: Prevalence, effects of treatment on productivity and cost benefit analysis in five districts of Punjab, Pakistan

The present study reports the prevalence, effects of treatment and cost benefit analysis of bovine fasciolosis in five districts of Punjab Province viz Sargodha, Jhang, Muzaffargarh, Lodhran and Layyah. From each of the five districts, 80 animals were selected and fortnightly screened through standard coprological procedures for a period of one year for the presence of eggs of Fasciola species. Of 4800 faecal samples analyzed, 1222 (25.46%) were found positive for fasciolosis. The occurrence of Fasciola (F.) gigantica (22.40%) was higher (P < 0.05) than F. hepatica (3.06%). Highest month-wise prevalence (P < 0.05) of fasciolosis was found in winter (39.08%) followed in decreasing order by spring (29.50%), autumn (20.33%) and summer (12.92%). District-wise prevalence of fasciolosis was highest (P < 0.05) in Sargodha (40.31%) and lowest in Layyah (11.77%) while other districts were having intermediate values of prevalence of fasciolosis. Species-wise prevalence of fasciolosis was found higher (P < 0.05) in buffaloes (30.50%) as compared to cattle (20.42%). However, there were no age and sex-related differences (P > 0.05) in prevalence of fasciolosis. A strong positive association of grazing (OR = 1.81), mixed farming of small and large ruminants (OR = 1.39), stagnant pond bathing (OR = 2.24) and river/canal bathing (OR = 2.06) was found with the prevalence of fasciolosis as compared to stall feeding, separate farming of small and large ruminants and rivers/canal/ tap water bathing, respectively. Post-treatment average milk increase of 0.62 L per animal per day with 0.35% higher fat was observed in fasciolicide-treated animals with the cost benefit ratio of 3.9. The results provided significant data on the epidemiology of five districts of Punjab province which may be helpful for the planners and small holder dairy farmers for control of fasciolosis in the study districts.     

Reclamation and salt leaching efficiency for tile drained saline‐sodic soil using marginal quality water for irrigating rice and wheat crops

Due to increased population and urbanization, freshwater demand for domestic purposes has increased resulting in a smaller proportion for irrigation of crops. We carried out a 3‐year field experiment in the Indus Plains of Pakistan on salt‐affected soil (EC_e 15·67–23·96 dS m⁻¹, pH_s 8·35–8·93, SAR 70–120, infiltration rate 0·72–0·78 cm h⁻¹, ρ _b 1·70–1·80 Mg m⁻³) having tile drainage in place. The 3‐year cropping sequence consisted of rice (Oryza sativa L.) and wheat (Triticum aestivum L.) crops in rotation. These crops were irrigated with groundwater having electrical conductivity (EC) 2·7 dS m⁻¹, sodium adsorption ratio (SAR) 8·0 (mmol L⁻¹)^1/2 and residual sodium carbonate (RSC) 1·3 mmol_c L⁻¹. Treatments were: (1) irrigation with brackish water without amendment (control); (2) Sesbania (Sesbania aculeata) green manure each year before rice (SM); (3) applied gypsum at 100 per cent soil gypsum requirement (SGR) and (4) applied gypsum as in treatment 3 plus sesbania green manure each year (GSM). A decrease in soil salinity and sodicity and favourable infiltration rate and bulk density over pre‐experiment levels are recorded. GSM resulted in the largest decrease in soil salinity and sodicity. There was a positive relationship between crop yield and economic benefits and improvement in soil physical and chemical properties. On the basis of six crops, the greatest net benefit was obtained from GSM. Based on this long‐term study, combined use of gypsum at 100 per cent soil gypsum requirement along with sesbania each year is recommended for soil amelioration and crop production. Copyright © 2010 John Wiley & Sons, Ltd.