Evaluation of Application Frequency and Levels of Nitrogen on Cactus Pear

The objective of this study was to evaluate the agronomic characteristics of Nopalea cochenillifera (L.) Salm-Dick under different frequencies and levels of nitrogen application (N). Three nitrogen fertilizer application frequencies (1 time year -1 , 6 times year -1 and 12 times year -1 ) and four nitrogen levels (0, 100, 200 and 400 kg of N ha -1 year -1 ) were evaluated one year after the planting, in a randomized blocks design with 12 replications. There was no interaction (P>0.05) between application frequencies and nitrogen levels. The number of cladodes, and the green and dry forage mass yields of the cactus pear were higher with the application frequency of 6 times year -1 , presenting 18.4 ± 2.0 cladodes per plant, 151.0 ± 17.8 and 9.8 ± 1.0 t ha -1 , respectively. The yield doubled with the application of 400 kg N ha -1 , when compared to the treatment with no nitrogen application. With the nitrogen application frequency of 1 time year -1 the crude protein and neutral detergent fiber contents were higher, presenting 4.0 ± 0.1% and 33.8 ± 0.5%, respectively. When nitrogen is applied 6 times year -1 it provides higher growth and yield, but lower protein and fiber contents. The level 400 kg N ha -1 provides higher yield and lower nitrogen use efficiency.