caa a22 4500 463208765 CHVBK 20180405153134.0 cr unu---uuuuu 170326e20070301xx s 000 0 eng 10.1007/s10705-006-9064-4 doi (NATIONALLICENCE)springer-10.1007/s10705-006-9064-4 Can local Minjingu phosphate rock replace superphosphate on acid soils in Tanzania? [Elektronische Daten] [C. Szilas, J. Semoka, O. Borggaard] Locally occurring Minjinju phosphate rock (MPR) in direct application as P source for maize production was compared with water-soluble imported, processed triplesuperphosphate (TSP) in a field study over three seasons on ten important, low-fertility agricultural soils throughout sub-humid to humid Tanzania. Except for the first season, where MPR was slightly inferior to TSP, direct application of MPR gave the same yields as TSP indicating that MPR can replace TSP on acid, severely weathered tropical soils low to very low in available P and exchangeable Ca and with high to very high phosphate adsorption capacity. Similar response for granulated and non-granulated MPR enables replacement of the dusty finely powdered MPR by the user-friendly granulated form. However, P fertilization improved maize yields on only three soils because plant growth is also limited by other factors than P, such as frost (one site) and lack of water and other nutrients, e.g. B, Cu and Mg. Apart from saving foreign currency, replacement of TSP by MPR has additional advantages because MPR contains calcium carbonate (lime effect), Mg, K, Cu and Zn. On the other hand, economy constrains MPR use as MPR was found to be economically competitive with TSP only in areas within about 700km from the mine, mainly because of current very high transportation costs. It may therefore be concluded that despite clear advantages of replacing TSP by MPR, climatic, economic and nutritional constraints must be dealt with in order to ensure improved and sustainable crop yields through use of MPR in direct application in Tanzania. Springer Science+Business Media B.V., 2006 Agronomic performance nationallicence Fertilizer nationallicence Maize yield nationallicence Competitiveness nationallicence P deficiency nationallicence Multiconstraint crop production nationallicence Szilas C. Watertech, Algade 52, DK-4000, Roskilde, Denmark aut Semoka J. Soil Science Department, Sokoine University of Agriculture, P.O. Box 3008, Morogoro, Tanzania aut Borggaard O. Department of Natural Sciences, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark aut Nutrient Cycling in Agroecosystems Kluwer Academic Publishers 77/3(2007-03-01), 257-268 1385-1314 77:3<257 2007 77 10705 https://doi.org/10.1007/s10705-006-9064-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10705-006-9064-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Szilas C. Watertech, Algade 52, DK-4000, Roskilde, Denmark aut NATIONALLICENCE 700 1- Semoka J. Soil Science Department, Sokoine University of Agriculture, P.O. Box 3008, Morogoro, Tanzania aut NATIONALLICENCE 700 1- Borggaard O. Department of Natural Sciences, Royal Veterinary and Agricultural University, Thorvaldsensvej 40, DK-1871, Frederiksberg C, Denmark aut NATIONALLICENCE 773 0- Nutrient Cycling in Agroecosystems Kluwer Academic Publishers 77/3(2007-03-01), 257-268 1385-1314 77:3<257 2007 77 10705 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer