Ammonium chloride as an alternative source of nitrogen for sugarcane during two consecutive cycles

Cloreto de amônio como fonte alternativa de nitrogênio para cana-de-açúcar durante dois ciclos consecutivos

Abstract:

The objective of this work was to evaluate the effect of the application of ammonium chloride as a nitrogen source for sugarcane (Saccharum sp.) on the development of the crop’s shoot and roots during two consecutive cycles. The experiment was conducted on a Typic Hapludox in the first and second sugarcane ratoons. The treatments consisted of four N doses (50, 100, 150, and 200 kg ha^-1) applied as ammonium chloride (NH₄Cl), besides a control, without the application of N. The increase in the NH₄Cl dose increased in up to three times soil electrical conductivity in the layer of 0.0-0.2 m, with a consequent increase in the concentration of chlorine in leaves. In the second cycle, the contents of chlorine increased in 1,900 mg kg^-1 in the leaf with the application of 200 mg kg^-1 NH₄Cl, when compared with the control. In the first cycle, the application of NH₄Cl doses above 200 kg ha^-1 N promoted a decrease in shoot productivity. In both cycles, there was no effect of the NH₄Cl doses on root dry matter. High doses of NH₄Cl, in consecutive sugarcane cycles, result in a decrease in the productivity of stalks for processing.

Index terms:
Saccharum; electrical conductivity; nitrogen fertilization; root system; stalk productivity