Screening for Water Saving Traits of Common Fodder Grasses Used in Integrated Crop-Livestock-Forestry Systems of Central West Brazil

Publikations-Art

Kongressbeitrag

Autoren

Glatzle, S., Giese, M., Asch, F.

Erscheinungsjahr

2015

Veröffentlicht in

Management of land use systems for enhanced food security: conflicts, controversies and resolutions

Verlag

Cuvillier Verlag , Göttingen

Seite (von - bis)

235

Tagungsname

Tropentag 2015

Tagungsort

Berlin

The humid subtropical climate of central west Brazil mostly provides sufficient rain-fall and adequate temperatures to support year-round agriculture production in in-tegrated tree-crop-livestock production systems. However, high rainfall variabilityduring the drier winter is increasingly compromising one of the most productive agri-cultural regions in Brazil. In addition, climate scenarios indicate up to 30 % lessrainfall during winter and increasing frequency of dry periods for central-south Brazilwithin the forthcoming decades. Information focusing on plant water use dynamicsof intergrated crop-livestock-forestry systems is rare and insufficient to estimate thesystem’s adaptive capacity to temporal water limitations and climate variability orchange. The objective of this research is to characterise whole plant transpiration ofselected common cultivated fodder grasses in response to atmospheric drought andshading.Whole plant transpiration rates [mmol m−2s−1] of the fodder grassesBrachiariabrizanthacv. Marandu,Brachiaria humidicolacv. Llanero,Brachiaria decumbens,Brachiaria ruziziensis,Panicum maximumcv. Mombaca andPanicum maximumcv. Tanzania was measured in a transpiration chamber with adjustable atmosphericvapour pressure deficits (VPD) and three different radiation intensities (420molm−2s−1, 730mol m−2s−1, 1200mol m−2s−1).The results show that with increasing vapour pressure deficit and radiation intensitythe transpiration rates for each fodder grassspecies increased linear but with differentslopes. While under low VPD levels the radiation impact on transpiration rates wasrather small, the effect was considerably increased under high VPD levels.Our results suggest that common cultivated fodder grasses in Brazilian pastures revealdifferent response dynamics to light intensity and VPD. Both abiotic factors are highlyvariable within integrative crop-livestck forestry systems and improved understandingof the plant’s water use traits will contribute to a resource use efficient, climate smart,and sustainable land use management.