Potential groundwater recharge zones within New Zealand

Water resources in New Zealand are not evenly distributed across the country which makes it difficult to adequately allocate the use of water resources in every basin. Groundwater is a fundamental water resource in New Zealand for agricultural, industrial and domestic use. Detailed knowledge regarding groundwater recharge potential is a pre-requisite for sustainable groundwater management, including the assessment of its vulnerability to contamination by pollutants. In this study, a comprehensive GIS approach was used to map the potential groundwater recharge zones across New Zealand. National data sets of lithology, slope, aspect, land use, soil drainage and drainage density were converted to raster data sets with a spatial resolution of 500 m x 500 m and superimposed to derive groundwater potential zones. The resultant maps demonstrate that the potential is low in urban and mountainous areas, such as the Southern Alps, whereas the highest potential can be found in regions with large lakes and in the lower elevation plains areas, where Quaternary sediments prevail. The resulting maps can be used to identify areas of high nutrient leaching in zones where high groundwater recharge potential exists.

Sorghum germplasm from West and Gentral Africa maintained in the ICRISAT genebank: Status,gaps,and diversity

The genebank at ICRISAT maintains 8020 accessions of sorghum from 16 West and Central African countries. Geographical gaps and diversity were assessed in the collection. Using the passport data of 3991 accessions for which georeferenced data were available, a total of386 districts(gaps) located in 11 West and Central African countries were identified as geographical gaps. Burkina Faso with 140 and Nigeria with 118 districts were identified as countries with major geographical gaps. The collection of 43 accessions of wild species represented only three species belonging to Sorghum bicolor ssp. drummondii and ssp.verticilliflorum, S. hevisonii, and S. macrochaeta, highlighting the need for collection missions aimed exclusively at enriching the collection of wild relatives. Accessions having characterization data(7630) were used to assess diversity. The first three principal components contributed to >60% of variation. Maximum diversity was observed in the collection from Nigeria for both qualitative and quantitative traits. Mean values indicated significant differences between basic and intermediate races for the traits studied. Among the races, accessions of guinea-caudatum for qualitative traits and those of caudatum for quantitative traits were highly diverse. The low intensity of the sorghum collection and the many geographical gaps in the collection underline the importance of launching collection missions to fill the gaps, particularly in regions of predominantly guinea sorghums.Genotyping of possible duplicate accessions is needed to identify duplicates in the collection. It is suggested that all passport information including georeferenced data of collection sites should be collected when samples are collected in gaps.