Growth and light environment of fruit trees in silvipastoral systems for rearing of dairy herds

Abstract

Silvopastoral systems can have animal welfare and sustainability benefits because trees continually remove carbon from atmosphere, reducing greenhouse effects. Thisstudy identified the most promising fruit trees for inclusion in silvopastoral systems to dairy cattle calves. This experiment was conducted at EmbrapaAgrossilvipastoril, Brazil, between 2014 and 2018. Five silvopastoral systems with fruit trees and ‘Tifton-85’ grass were designed to evaluate tree growth and light environment under the canopies. Data were analyzed using SAS® and PDIFF (P < 0.10). Caja fruit trees had the greatest tree height (5.4 m) and trunk diameter (23.4 cm), while acerola fruit tree had the smallest (1.8 m and 8.3 cm, respectively). At 42 months (drought 2017), caja, cashew, and guava trees had similar heights. Guava trees had the highest light interception (89.3%), both cashew cultivars provided medium levels of shade (50 to 60% LI) and with greater constancy between the rainy and dry seasons. The systems that showed increased light interception during the drought period were those with CCP76 in 2017 and EMB51 in 2018. Higher incidences of wavelengths of the spectral composition of light occurred between the rainfall (2015) and drought (2017) periods, and greater differences in the ratio of red:far red in 2015. By 2018, there were no more differences between the rainy and dry seasons for the spectral composition of light under the tree canopies. Cashews and guava trees have adequate growth and light environment to support silvopastoral systems but Caja and acerola fruit trees showed limitations.