Non-PR | IFPRI4 | TMD

The most stable forms of organic matter in soils are the clay–humic complexes. An understanding of mechanisms and processes influencing the formation of clay–humic complexes may facilitate development of agricultural management systems that increase the long-term sequestration of C in soils and improve soil quality. The specific objective of this study was to visualize associations between humic substances and clay minerals separated from a typical agricultural soil. The soil sample used in this study was from the Ap horizon of a Webster (fine-loamy, mixed, superactive, mesic Typic Endoaquoll) soil located near Waseca, MN. The whole soil clay fraction (<2 μm particle-size fraction) was separated by a relatively mild sedimentation technique, and coarse, medium, and fine clay fractions (0.2–2.0, 0.02–0.2, and <0.02 μm size fractions, respectively) were separated from a portion of the whole clay sample by an aggressive sonication-centrifugation technique. All samples were Ca-saturated, dialyzed, and freeze-dried. The samples were analyzed by scanning electron microscopy to obtain images of clay–humic complexes and energy dispersive x-ray analysis to obtain maps of elemental distributions. Two distinct types of clay-associated humic substances were identified. The first type exists as diffuse filamentous films that cover basal surfaces of 2:1 phyllosilicates in the medium and fine clay fractions. The second type exists as discrete particles of high-density metal–humic substance complexes in the coarse clay fraction.

Soil management systems that encourage the formation and stabilization of recalcitrant clay–humic complexes will have the greatest long-term impact on C sequestration and soil quality. The objective of this study was to determine the relationship between the chemical, biochemical, and spectroscopic characteristics of humic substances and clay mineralogy. Clay–humic complexes were separated from the Ap horizon of a Webster soil (fine-loamy, mixed, superactive Typic Endoaquoll) by an invasive sonication–centrifugation technique. The samples were analyzed for mineralogy by XRD (x-ray diffraction), chemical composition by inductively coupled plasma-atomic emission spectorscopy (ICP-AES), C and N by thermal combustion, C chemistry by solid state ¹³C magic angle spinning-nuclear magnetic resonance spectroscopy (MAS-NMR) and both gas chromatography (GC) and high performance liquid chromatography (HPLC) analyses of extractable organic compounds. The coarse, medium, and fine clay fractions are dominated by quartz, a low-charged interstratified phase, and smectite, respectively. Extractable organic compounds, 30 to 52% of the total C, are dominated by basic amino acids and polyunsaturated fatty acids. Less than 3% of the extractable C is monosaccharides and amino sugars and only trace levels of phenolic acids were found. The C/N ratios of humic substances associated with the coarse, medium, and fine clay fractions are 17, 10, and 10, respectively. The coarse clay fraction has stronger carboxyl and O-alkyl ¹³C-NMR peaks and lower levels of extractable amino acids, fatty acids, monosaccharides, and amino sugars than humics associated with the fine clay fraction. The results indicate that the biochemistry of the clay–humic complexes differs substantially from that of whole soils and that soil clay mineralogy strongly influences humification.

Genus Fagopyrum consists of two cultivated buckwheat species viz. mithe (common) (F. esculentum) and tite (tartary)(F. tartaricum). Both species are under cultivation since time immemorial in Nepal. Buckwheat is one of the mandatory crops of Hill Crops Research Program (HCRP) and is an important staple food crop in high hills. Tite buckwheat is more important in higher elevation. Under varietal improvement work on buckwheat a number of activities have been carried out by HCRP, Kabre. Separate sets on mithe and tite buckwheat experiments are being tested. Observation nurseries have been tested in two-row plot basis while Initial Evaluation Trial (IET) and Coordinated Varietal Trial (CVT) in lattice design. Seven activities viz. National Observation Nursery (NON) (mithe and tite), IET (Mithe and tite), CVT (Mithe and tite) and Farmer field Trial (FFT) (mithe) are carried out under varietal improvement work. This paper consists of the finding of Agriculture Research Station, Jumla (2350 masl), Agriculture Botany Division, Khumaltar (1350 masl) and HCRP, Kabre (1740 masl) in 1999 and 2001. In advance observation nursery, AccNo. 481, CBBP-03, IR-13, AccNo. 6529 were promising in mithe genotypes while AccNo. 5170, AccNo. 7529, AccNo. 2193 and sample No. 6-1 were superior genotypes in tite at Kabre, Jumla and Khumaltar. Genotypes GF-5139 DARZA and local mithe were found promising in mithe while genotypes MY-2-27-1, AccNo. 2227-1 and local tite were high yielding in tite under IET. In CVT (mithe), local mithe, GF-5274, GF-5099 and in CVT (tite), AccNo. 2223, GF-212, AccNo. 2230, AccNo. 2227 were promising at Kabre and Jumla. In FFT, GF-5274, IR-13 and GF-5283 were superior in mid hills. Diversed yield potential of these genotypes indicates the possibility of developing high yielding varieties suitable to different sites.

Buckwheat (Fagopyrum esculentum Moench.) is a pseudo cereal and traditional food crop in different parts of the world. It is endemic crop of China and cultivated in mountainous regions of Central and Western China. In Nepal cultivation of buckwheat is limited to hills because the hilly people have no other choice except maize, potato, amaranth, barley and finger millet. Buckwheat is inter-cropped with potato and also grown as a sole crop in hilly areas of Nepal. ABT-4 rooting powder, a new type of growth regulator has been used in the present investigation. ABT-4 rooting powder 5,10,15 and 20 ppm solutions were prepared as per the method of Wang, 1993. Healthy seeds of buckwheat were soaked and sown in earthen pots and fields. Concentration of 5,10 and 15 ppm of ABT-4 rooting powder significantly increased percentage of seed germination, seedling growth, chlorophyll contents and yield parameters. ABT-4 of 15 ppm showed the most significant effect on all the parameters studied, however, 20 ppm ABT-4 rooting powder showed inhibitory effect on all parameters.

The agricultural crops grown in the mountain areas are showing considerable decline in productivity. The lack of visit by sufficient insect pollinators in the crop field is supposed to be one of the important factors for such a decline in productivity of the crops. For the production of better quality and yield of seeds, adequate pollination of crop is essential. Since most crops are completely or incapable of pollinating themselves, cross pollination of these flowers by the pollinating insects is indispensable. In Nepal, people living in the mountains regard special value to the buckwheat crops. It is because its input costs are very low, easy to grow even when other crops fail. It is adaptive to adverse climatic condition, well fitted in the sustainable farming system and helps to fulfill the precarious food needs of the hungry people. According to Rajbhandari and Hatley, 1991/92 the yield of buckwheat crop is 600 to 800 kg ha. This indicates that both the production and productivity of this crop needs to be elevated to keep pace with the growing demands of the population residing in the mountain and remote areas. In the present study, the potential of buckwheat crop through mobilization of honeybee colonies has been tried to explore expecting better pollination towards increased fertility and seed yield. The field experimentation will be done at RECAST, Tribhuvan University, Nepal

The report proposes key elements for an agricultural export-oriented strategy in Egypt, that would build on the achievements of the agricultural strategy during the 1990s. Substantial improvements in the country's macroeconomic environment, following policy reforms - though necessary - have not been sufficient to improve agricultural export performance. Overall, while Egyptian agricultural production increased during the 90s, agricultural exports remained low, and, the fact that both Egyptian production, and world market trends are substantially less volatile, is a first indicator of the potential to increase agricultural exports. The proposed agricultural export strategy starts with an analysis of the agricultural export potential in the country, which includes a review on the overall agricultural export performance; an analysis of the incentive framework in agriculture, including estimates of the current nominal, and effective protection rates of key imports, and exports, and, the estimated effects of alternative agricultural, and trade policy reform scenarios, on the returns to farming in alternative crops. This analysis identifies two agricultural sub-sectors - cotton and horticultural crops - from which Egypt, contingent on policy reforms, could benefit from potentially substantial comparative advantages in trade. Based on the recognition that export promotion requires a mix of sector-wide, and sub-sector specific reforms, the rational focus of the report was to identify the main impediments of export growth in the cotton, and horticultural sectors. The report further offers suggestions to phasing in reforms, so that policies increasing farming returns in exports, precede those that will decrease (absolute) returns in competing crops.

This Research Reports surveyed agricultural R&D capacity in the Caribbean in order to gain better insight into its structure and development, as well as its potential contribution to the development of agriculture in the region. The main findings of the study are: (a) agricultural research capacity in the Caribbean is highly fragmented, (b) between 1986 and 1996, the growth in agricultural research capacity in the Caribbean almost halted in terms of the number of researchers, and contracted in terms of expenditures, (c) nevertheless, agricultural research investment levels relative to AgGDP are rather high for many of the smaller Caribbean countries, but not high enough to provide sufficient technology, and (d) commodity specialization and clustering of research activities across countries are some ways of creating enough volume of research benefits to pay for research costs.