As part of a strategy ofproviding recommendations for the use of ammonium sulphate (AS) fertiliser (21 % N) in various soils of the Southern Highlands of Tanzania, a long term trial was initiated in 1982-83 to investigate the acidifying effect of the fertiliser at low (50 kg Nlha), medium (100 kg Nlha), and high (150 kg N/ha) rates of fertilisation. The trial was located at Uyole (1,800 masl, Luvic phaeozems), Mbimba (1,500 mas/, Haplic phaeozems), /smani (1,400 mas/, Chromic cambiso/s), Mita/ula (1,100 mas/, Eutric nitoso/s), Su/uti (1,000 mas/, Acri-dystric regoso/s), and Ndengo (1,800 masl, Haplic acrisols). The trial was maintained on the same plots for five consecutive years. A significant soil pH drop (P =0.05) was noted after five years in five out of six locations. The higher the rate ofAS application the greater was the drop in soil pH. Maize grain yields were not significantly affected by the decreasing soil pH.

Text in English

SEP archives