Pinyon Pine and Juniper Biochar Application to Four Eastern Nevada Soils.

Pinyon pine and juniper encroachment into agricultural areas of the arid, western US affects an estimated 43 million acres.  Species removal and subsequent biochar creation for use as a soil conditioner in affected areas may be beneficial in terms of nutrient and soil moisture status, and may improve plant growth.  Over a four month incubation period, we studied the effect of increasing pinyon or juniper biochar application rates (0, 1, 2, and 5% by weight) on four eastern Nevada soils in areas affected by encroachment.  Soil pH was altered by no more than 0.2 units, while EC tended to decrease with increasing biochar application rate potentially due to excess salt sorption onto biochar.  Reductions in soil NO₃-N and increases in soil organic C with increasing biochar application rate occurred as expected.  The availability of several micronutrients increased, but not above a concentration considered optimal for plant growth.  Perhaps the single most important observation was an increase in soil moisture content at the 1% biochar application rate as compared to other rates.  This increase correlated with an increase in alfalfa germination rates.  Armed with this knowledge, biochar land applicators could bracket increases in soil water status and subsequent plant growth under limited irrigation or rainfall situations.