Intensification-induced Degradation of Irrigated Infrastructure: The Case of Waterlogging and Salinity in Pakistan

Water and land development, use, and distribution has played a vital role in agricultural development in Pakistan. The country's canal irrigation system is the largest contiguous irrigation system in the world-consisting of 40,000 miles of canals and over 80,000 water courses, field channels and ditches running for another million miles [Qureshi and Zakir (1994)]. This irrigation network covers more than 70 percent of Pakistan's agriculture. Private investment has also contributed significantly to the irrigation system in the form of private tubewells. About 32 percent of farm-gate available water is supplied by the private tubewells, [Government of Pakistan (1988)]. These develoPlIlents have not only brought new land under cultivation but also permitted a considerable increase in cropping intensities

Maize in Nepal: Production Systems, Constraints, and Priorities for Research

Crop Production/Industries, Research and Development/Tech Change/Emerging Technologies,

Beyond romance and rhetoric: sustainable agriculture and farming systems research

Sustainable agriculture, Farming systems, Agriculture, Research

Telescopic hybrid fast solver for 3D elliptic problems with point singularities

This paper describes a telescopic solver for two dimensional h adaptive grids with point singularities. The input for the telescopic solver is an h refined two dimensional computational mesh with rectangular finite elements. The candidates for point singularities are first localized over the mesh by using a greedy algorithm. Having the candidates for point singularities, we execute either a direct solver, that performs multiple refinements towards selected point singularities and executes a parallel direct solver algorithm which has logarithmic cost with respect to refinement level. The direct solvers executed over each candidate for point singularity return local Schur complement matrices that can be merged together and submitted to iterative solver. In this paper we utilize a parallel multi-thread GALOIS solver as a direct solver. We use Incomplete LU Preconditioned Conjugated Gradients (ILUPCG) as an iterative solver. We also show that elimination of point singularities from the refined mesh reduces significantly the number of iterations to be performed by the ILUPCG iterative solver

Genetics, fertility behaviour and molecular marker analysis of a new TGMS line, TS6, in rice

The thermosensitive genic male sterility (TGMS) system has great potential for revolutionizing hybrid rice production through simple, less expensive and more efficient seed production technology. For the successful utilization of this novel male sterility system, knowledge of the breeding and fertility behaviour of a TGMS line is essential. In this study, the fertility transformation behaviour, the critical fertility and sterility temperatures and the mode of inheritance of male sterility were studied for a new TGMS line, TS6, identified at Tamil Nadu Agricultural University, Coimbatore, India. The pollen and spikelet fertilities recorded on plants raised at fortnightly intervals revealed that this line was completely sterile for 78 consecutive days (35/22 to 32/23�C, maximum/minimum temperatures) and reverted to fertile when the temperature was 30/18�C. It remained fertile continuously for 69 days and the maximum pollen and spikelet fertilities recorded were 75 and 70%, respectively. The fertility was highly influenced by daily maximum temperature followed by average and minimum temperatures. It was not influenced by relative humidity, sunshine hours or photoperiod. The critical temperature inducing sterility and fertility was 26.7 and 25.5�C, respectively. The male sterility in TS6 was inherited as a monogenic recessive in the F2 and BC1 populations of TS6 · MRST9 as well as TS6 · IR68281B. Using bulked segregant analysis on an F2 population of TS6 · MRST9, an RAPD marker, OPC052962, was identified to be associated with TGMS in TS6

Distant agricultural landscapes

This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. The final publication is available at Springer via http://dx.doi.org/10.1007/s11625-014-0278-0This paper examines the relationship between the development of the dominant industrial food system and its associated global economic drivers and the environmental sustainability of agricultural landscapes. It makes the case that the growth of the global industrial food system has encouraged increasingly complex forms of “distance” that separate food both geographically and mentally from the landscapes on which it was produced. This separation between food and its originating landscape poses challenges for the ability of more localized agricultural sustainability initiatives to address some of the broader problems in the global food system. In particular, distance enables certain powerful actors to externalize ecological and social costs, which in turn makes it difficult to link specific global actors to particular biophysical and social impacts felt on local agricultural landscapes. Feedback mechanisms that normally would provide pressure for improved agricultural sustainability are weak because there is a lack of clarity regarding responsibility for outcomes. The paper provides a brief illustration of these dynamics with a closer look at increased financialization in the food system. It shows that new forms of distancing are encouraged by the growing significance of financial markets in global agrifood value chains. This dynamic has a substantial impact on food system outcomes and ultimately complicates efforts to scale up small-scale local agricultural models that are more sustainable.The Trudeau Foundation || Social Sciences and Humanities Research Council of Canad