Effects of compost level in soil and season on the production and composition of cactus varieties
Keywords:Cactus, compost, fiber, protein, minerals, in vitro digestibility.
The objective of this research was to determine the effect of adding compost on nutritive value
of cactus cladodes during the four seasons of the year. The production, chemical composition,
and in vitro digestibility of a cactus variety with spines (WS) and a cactus variety without spines
(WOS), were subjected to a complete block design with three quantities of compost (0, 61 and
122 t ha-1) and four seasons (summer, fall, and winter 2013 and spring 2014). The WS variety
produced more dry matter (DM) (p=0.035) and crude protein (CP) (p=0.037) than the WOS
variety. Although CP, fiber constituents, and mineral composition of cactus varied (p<0.001)
with respect to season of the year, in vitro DM digestibility did not differ (p=0.29) across
seasons. Both cactus varieties had high ash (29.0 to 29.2%) and moisture (89.5 to 91.7%)
contents. Adding compost to the soil improved (p<0.001) the average DM production of both
cactus varieties. Compost addition also increased the lignin (p=0.008), phosphorus (p<0.001)
and zinc (p=0.025) concentrations and reduced (p=0.04) the in vitro DM digestibility. The high
ash and moisture contents of cactus could reduce the densities of energy and other nutrients
that are consumed by livestock.