The Need And Prospects For Agrotechnology Transfer

Many people in the world today do not receive enough food, and the prospects for the future are depressing. The deficits in staple foods in the developing countries are likely to be three to four times as great in 1990 as they are today. There is need for more intensive use of soils, but there is already much concern about the deterioration of soils throug- h excessive and unwise use. Agricultural research can contribute significantly to the amelioration of these problems, but because research costs are high and increasing, efforts are needed to make agricultural research more efficient. Many small countries will not have the resources to make the magnitude of research effort needed to solve their own problems. In these dire circumstances, greater efforts need to be made to transfer agricultural technology from place to place and country to country. Presently it is being done mostly by trial and error, but more scientific approaches are being developed. Models that simulate biological processes and regression equations relating crop performance to input and sitefactor variables have great potential but only limited success to date, because of the magnitude of environmental site-factor constraints. Methods of analogous transfer have much greater immediate value. They are widely if casually used. They can be made more useful and more scientific if they are based upon the stratification of resource and environmental constraint variables, particularly of climates and soils. A methodology for systematic, analogous agrotechnology transfer now exists in the combination of soil survey, Soil Taxonomy, the benchmark soils concept, and the methods of soil survey interpretation. Some useful scientific proofs have been made of the transfer methodology over a global soils network, far exceeding in its geographic coverage the current possibilities of simulation or statistical methods. It is easy to see how the number of stations in the network can be increased through an International Benchmark Soils Network. The new methodology opens up the real possibility of technical communication and cooperation among the developing countries. It opens up the real possibility of increasing the efficiency of agronomic research. It opens up the need for countries to know their soils better and to strengthen their programs of soil survey interpretation. It opens up the possibilities for much greater and more effective use of soils information in the planning of agricultural development. An operating network of stations for agrotechnology transfer will not decrease the need for national agricultural research, because there is proof that transfer will not occur in the absence of local research capacity. Research in developed countries and in the international agricultural centers assists the transfer process, but does not replace the need for national research

A time for rainfed agriculture: Eleventh Coromandel Lecture

In this lecture a plea is made for the study and promotion of increased agricultural production and stabilization of crop yields in rainfed areas of India, based on experience gained by the author in different parts of the world and particularly at ICRISAT. The increasing pressure of population on land resources in India, and particularly the weather, makes it essential to get the maximum food production both from irrigated and rainfed areas. Out of 142 ha of cultivated land in India, about 108 mill ha depend on rainfed agriculture, accounting for 42% of foodgrains production. Average yields are low, generally below 800 kg/ha. It is possible to increase the yields by 50 to 100% with the existing technologies. The contribution of improved, input-responsive seeds and fertilizers, improved management of soil and rainfall, proper choice of cropping systems, supplementary irrigation and water harvesting in rainfed areas, and adoption of full packages of practices will enable modern agriculture and higher production and farm incomes to spread throughout the rainfed area

A time for rainfed agriculture

In this lecture a plea is made for the study and promotion of increased agricultural production and stabilization of crop yields in rainfed areas of India, based on experience gained by the author in different parts of the world and particularly at ICRISAT. The increasing pressure of population on land resources in India, and particularly the weather, makes it essential to get the maximum food production both from irrigated and rainfed areas. Out of 142 ha of cultivated land in India, about 108 mill ha depend on rainfed agriculture, accounting for 42% of foodgrains production. Average yields are low, generally below 800 kg/ha. It is possible to increase the yields by 50 to 100% with the existing technologies. The contribution of improved, input-responsive seeds and fertilizers, improved management of soil and rainfall, proper choice of cropping systems, supplementary irrigation and water harvesting in rainfed areas, and adoption of full packages of practices will enable modern agriculture and higher production and farm incomes to spread throughout the rainfed areas

Self-organization and the selection of pinwheel density in visual cortical development

Self-organization of neural circuitry is an appealing framework for understanding cortical development, yet its applicability remains unconfirmed. Models for the self-organization of neural circuits have been proposed, but experimentally testable predictions of these models have been less clear. The visual cortex contains a large number of topological point defects, called pinwheels, which are detectable in experiments and therefore in principle well suited for testing predictions of self-organization empirically. Here, we analytically calculate the density of pinwheels predicted by a pattern formation model of visual cortical development. An important factor controlling the density of pinwheels in this model appears to be the presence of non-local long-range interactions, a property which distinguishes cortical circuits from many nonliving systems in which self-organization has been studied. We show that in the limit where the range of these interactions is infinite, the average pinwheel density converges to $\pi$. Moreover, an average pinwheel density close to this value is robustly selected even for intermediate interaction ranges, a regime arguably covering interaction-ranges in a wide range of different species. In conclusion, our paper provides the first direct theoretical demonstration and analysis of pinwheel density selection in models of cortical self-organization and suggests to quantitatively probe this type of prediction in future high-precision experiments.Comment: 22 pages, 3 figure

Coordinated optimization of visual cortical maps (II) Numerical studies

It is an attractive hypothesis that the spatial structure of visual cortical architecture can be explained by the coordinated optimization of multiple visual cortical maps representing orientation preference (OP), ocular dominance (OD), spatial frequency, or direction preference. In part (I) of this study we defined a class of analytically tractable coordinated optimization models and solved representative examples in which a spatially complex organization of the orientation preference map is induced by inter-map interactions. We found that attractor solutions near symmetry breaking threshold predict a highly ordered map layout and require a substantial OD bias for OP pinwheel stabilization. Here we examine in numerical simulations whether such models exhibit biologically more realistic spatially irregular solutions at a finite distance from threshold and when transients towards attractor states are considered. We also examine whether model behavior qualitatively changes when the spatial periodicities of the two maps are detuned and when considering more than 2 feature dimensions. Our numerical results support the view that neither minimal energy states nor intermediate transient states of our coordinated optimization models successfully explain the spatially irregular architecture of the visual cortex. We discuss several alternative scenarios and additional factors that may improve the agreement between model solutions and biological observations.Comment: 55 pages, 11 figures. arXiv admin note: substantial text overlap with arXiv:1102.335

Findings from a cluster randomised trial of unconditional cash transfers in Niger.

Unconditional cash transfers (UCTs) are used as a humanitarian intervention to prevent acute malnutrition, despite a lack of evidence about their effectiveness. In Niger, UCT and supplementary feeding are given during the June-September "lean season," although admissions of malnourished children to feeding programmes may rise from March/April. We hypothesised that earlier initiation of the UCT would reduce the prevalence of global acute malnutrition (GAM) in children 6-59 months old in beneficiary households and at population level. We conducted a 2-armed cluster-randomised controlled trial in which the poorest households received either the standard UCT (4 transfers between June and September) or a modified UCT (6 transfers from April); both providing 130,000 FCFA/£144 in total. Eligible individuals (pregnant and lactating women and children 6- 0.05), despite improved food security (p < 0.05), possibly driven by increased fever/malaria in children (p < 0.001). Nonfood related drivers of malnutrition, such as disease, may limit the effectiveness of UCTs plus supplementary feeding to prevent malnutrition in this context. Caution is required in applying the findings of this study to periods of severe food insecurity