EFFECT OF ZINC LEVELS FOR RICE IN A CERRADO SOIL

Abstract

In the present experiment, the effect of increasing doses of zinc sulphate on productivity and on the occurrence of symptoms of zinc deficiency was studied in upland rice grown in ‘cerrado’ soil. The experimental design was randomized blocks with six (6) treatments and four (4) repetitions. The zinc sulphate levels tested were 5, 10, 20, and 40 kg/ha., all of which were then compared to that of the control plot, and to a treatment which received a side dressing of amonia sulphate (40 kg/ha) in addition to the basic fertilizer and lime. The experiment was installed in red 'latossolo’, clay-lime base, with typical ‘cerrado' vegetation. The rice strain used was IAC—12/46, with the seeds having been disinfected with dry Neantina at 0.3%. To guage the results, the production of kernels and the degree of leaf browning were computed. The analysts of the data revealed that the treatments of zinc sulphate, in doses of 5, 10, 20, and 40 kg/ha., showed no significant difference statistically and more superior to the control plot and the one treated with amonia sulphate. It was concluded that application of zinc sulphate in the plant farrow, in the dose of 5 kg/ha., is sufficient to prevent the occurrence of intense zinc deficiency which is capable of provoking considerable decreases in the productivity of rice plants. The application of amonia sulphate, by itself, on the soil, in a dose of 40 kg/ha., didn’t prevent a drastic manifestation of the occurrence of zinc deficiency in the plants.