Experiments on sugar cane irrigation by furrow

This paper reports and discusses the first results referring to a field trial set up in the Experimental Station of Piracicaba, to determine the effects of furrow irrigation on sugar cane. Soil samples were taken from every plot at approximately two weeks intervals and at the depths of 0-25, 25-50, 50-75 and 75-100 cm, for soil moisture determination. Most of the roots of the sugar cane are found in the upper 50 cm layer of the soil. Irrigation should be planned when seventy percent of the available water in the layer has been used. If we assume an average of 50 mm water stored in the root zone available to the crop, the irrigation should be scheduled when the crop has used 36 mm of the soil water storage. The statistical analysis showed significant increase in sugar cane production between check plots and the plots irrigated under the previously mentioned conditions. The sugar cane production increase by irrigation was 46 t./ha. Concerning sugar, the statistical analysis showed significant increase in sugar production between check plots and the irrigated plots in favor of the irrigated plots. The sugar increase by irrigation practice was 6.1 t./ha. This date refer to the first harvest. In relation to the second harvest the same results occurred with sugar cane production 44.3 t./ha, and sugar 6.4 t./ha, respectively.