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The agricultural pattern of Mendoza, Argentina, has two main elements, an early-developed region of vineyards around Mendoza city, and a region to west, south, and east with more crop diversity and modern technology. Four principal factors contribute to the difference between these two, 1) climate; 2) the chronology of agricultural settlement; 3) land tenure; and 4) the manner of water provision. The Mendoza city region is associated with higher temperatures and longer growing season than the peripheral region, with earlier development of irrigated land, with backward forms of land tenure, and with only limited use of well water to aid river supplies. Both land tenure and water provision are changing factors with considerable impact on the rate of agricultural development. The probable qualitative effect of two further changes in water supply, high dams, and new water control legislation, is comparable to that of well use. By contrast, canal lining and river diversion are primarily quantitative a...

Conservation of crop genetic resources presents a challenge of identifying specific determinants driving maintenance of diversity at farm and agroecosystems. The objectives of this study were to identify socioeconomic, market and agroecological determinants of farmers’ maintenance of rice diversity at the household level and derive implications for policies in designing on-farm conservation programs. We assess spatial rice diversity at farm level using household survey data. A household decision making model is conceptualised using microeconomic theory to assess and identify factors influencing on-farm rice diversity. The model is then tested econometrically by using various factors affecting farmers’ variety choice and diversity decisions. The findings show that household-specific socioeconomic, agroecological and market factors are important in determining on-farm rice diversity. The significant variables in explaining richness and evenness of rice diversity include distance to the nearest market, subsistence ratio, modern variety sold, land types and adult labour working in agriculture. The statistical signs of the factors determining rice diversity are consistent in explaining the richness, dominance and evenness among rice varieties. Finally, the study implies that the cost-effective means of promoting and sustaining on-farm conservation programmes is to target them in market isolated geographic locations of high crop diversity where farm households have more heterogeneity of agroecological conditions and more active family adult labour working on-farm. Key words: Diversity indices; dominance; evenness; on-farm conservation; rice diversity; richness DOI: 10.3126/narj.v6i0.3370 Nepal Agriculture Research Journal Vol.6 2005 pp.49-5

In summarizing, the Ethiopian Center of Crop Diversity contains enormous wealth of genetic variability in the sorghums. It needs some concerted effort to adequately collect and preserve this genetic variability before it is invaded and destroyed by improved uniform varieties and modern technology. The Alemaya station has a limited collection of the Ethiopian sorghums, about 1800 entries. These collections have been very useful and will continue to be so in the sorghum breeding programs of Alemaya and the world at large.

Unexpected results derived from applications of chemicals to soils led to investigations of the soil biology, discovery of the rhizosphere and eventually to research on mechanisms of biological control. Decisively, chemicals have staved off major disasters in agriculture. In instances of successful monoculture, below ground pathogens appear to be suppressed by an injurious biology, in principle not unlike an injurious host-specific biology which increases with repeated cultivation of the same crop. Crop diversity, nevertheless, is basic to continued successful production agriculture. Decoy hosts which initiate germination of resisting structures may deplete pathogens of energy reserves, and serve to protect the major host. Endogone , which occupies root cortical tissue of most plants, in addition to the traditional mycorrhizal function, may afford protection against invasion by pathogens. Healthy Endogone may be essential to healthy crops.

1. The various crops under cultivation in Manchuria are cultivated with the different crop type of natural environmental factors.2. There are five crop types by the coefficients of correlation between the yield of various crops and the meteorological elements in 13 places.I Crop type—Cold temperature and more rainfall.II Crop type—High temperature and low rainfall.III Crop type—Indefinite relationship with the meteorological factors.IV Crop type—High temperature and more rainfall.V Crop type—Cold temperature and low rainfall.3. Each crop has no definite crop type and turned into another type when the crop removed from one place to another. Under most adapted place the crop shows “The Second Type.”4. The yield of tuber crop which shows “The Third type”, gives great variation by the management of tillage during its growth. Therefore the tuberous crop is one of the relief crop under the unfavorable climatic condition.5. We classified the various crop by the grade of temperature into groups.Cold-weather cropsWheat, Barley Oats, Rye, Flax Sugar beets Irish potatoes Perill, Alfalfa Sunflower Common milletWarm-weather cropsSorghum Italian millet Cotton Kenaf(Ambari hemp) Castor bean plant Indian mallowAnd there are crops distributed in both region such as, soybean, corn and rice plant (included upland rice).6. The cultivation area of soybean, corn and rice plant have large acreage in both region and there are difference more or less in the summation of temperature required by various varieties in each crop.7. The warm-weather crop as rice plant has special demand of high temperature and more rainfall during its growth. Generally it appears in the flowering period.8. The tuber crop shows “the Fifth Type” in the north and “the Third Type” in the middle part and we consider that the adapted area will be in further north.9. Reported the meteorological elements which have the maximum coefficient of correlation with crop yield (Table 12) and the important meteorological factors by every month between the crop yield in each district (Table 13).10. Since the low temperature in the end of the crop growth in the north, it demand the higher temperature, and as the drought during the growth in the middle and south, more rainfall is necessary. These phenomena are the general tendency in agriculture of Manchuria.11. We found the safety region in every crop by the yield and studied for the four phases by the meteorological elements. In the middle region there are many cases of the safety region in “the Second Phase” cold and wet and then in “the Fourth Phase” hot and dry and in “the Third Phase” cold and dry.The writer wishes to express his appreciation for the helpful suggestions of Dr. O. M. Mac Conkey. Senior Agricultural Offlce, United Nations of Relief and Rehabilitation Administration at Mukden Office.

CROP production in Britain is carried on in the hope of gain, and thus differs fundamentally from gardening, which is commonly practised without regard to profit and loss accounts. Many poets from times of old down to our own days have sung of the pleasures to be derived from gardening. But only once in the history of literature have the pleasures of farming been sung, and that was nearly two thousand years ago.