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11.
Rice is a major staple food in Afghanistan, and its production contributes to the food security for millions of Afghans. However,
over the past four decades, increases in rice cultivation in the Amu Darya River Basin in the northeastern part of the country
are contributing to head/tail inequities in irrigation water-sharing, both at river basin and at canal levels. Since 2007,
the Participatory Management for Irrigation System project has been experimenting with the System of Rice Intensification
(SRI) as an alternative to the highly water-consumptive traditional method of rice cultivation by inundation of fields. The
aim is to introduce a water-saving method for upstream rice-growing farmers to improve the water access for downstream users.
To the extent that such a method improves yield, this gives upstream farmers an incentive to switch to this new method which
benefits them and, indirectly, other farmers downstream. In 2009, 42 farmers who are cooperating with the Aga Khan Foundation
practiced SRI, facilitated through the project’s participatory technology development (PTD) approach. Their average SRI yield,
9.3 tons ha−1, was considerably higher than that obtained with their traditional rice-growing practices. Those farmers who had 2 years
of experience with SRI methods and who greater mastery of the techniques got, on average, 65% higher yield than first-year
SRI farmers. More-experienced farmers improved their rice production by 27% in comparison to their previous results in 2008.
The PTD approach engages the experienced farmers as resource persons to assist new volunteers, promoting local transfer of
knowledge. The primary factor in yield improvement was an increase in the number of grains per panicle (+47%). A 10% increase
in the number of tillers per square meter, despite lowered plant population, was the second major factor. Yields appeared
to be very responsive to an increased number of mechanical weedings. Challenges still remain to be dealt with on the way toward
up-scaling, especially as the security situation remains problematic. However, the PTD approach is facilitating work in the
field as is cooperation with government personnel. 相似文献
12.
Khiari Ramzi Meksi Nizar Mhenni Farouk Belgacem Mohamed Naceur Mauret Evelyne 《Fibers and Polymers》2011,12(5):587-593
The chemical composition of date palm rachis wastes, which are widely available cellulosic biomass-based agricultural crops
in Tunisia, were characterized to determine if they had the potential for use as a starting raw material to prepare cellulose
derivatives. To accomplish this, several sodium cellulose carboxylmethylates (NaCMCs) were prepared and tested as sizing agents
for coating yarn. The synthesis of NaCMC was conducted in n-butanol containing NaOH (40 %) as a solvent mixture and monochloroacetic
acid (MAC) as the etherifying reagent. The NaCMC samples were characterized based on their degrees of substitution (DS) and
polymerization (DP). The prepared NaCMC samples were then tested as sizing agents for cotton yarn in textile applications.
Specifically, different NaCMC samples were used to prepare a coating bath, which was then applied to size a cotton yarn textile.
The quality of the coated yarns was subsequently evaluated by determining three parameters, yarn hairiness, the load at break,
and the elongation at break. The sizing performances of the NaCMCs prepared from date palm rachis wastes were then compared
with those of commercial NaCMC. The values of hairiness, breaking load, and breaking elongation of some of the NaCMC-treated
yarns were as high as those prepared using commercial additives as sizing agents. These findings indicate that the cellulose
derivatives prepared in this study are good candidates for alternatives to currently available additives. 相似文献