Blue Grama Response to Nitrogen and Clipping Under Two Soil Moisture Levels

Abstract

Effects of N-fertilization and clipping on production and water use of blue grama were evaluated under two soil moisture levels, field capacity and 1/5 available water. Nitrogen increased shoot production 77% on unclipped plants. Clipping decreased shoot production 287% below the control averaged across N levels. Soil moisture levels produced no differences in yields. Root weights were decreased an average of 253% below the control by clipping. No differences were observed in total water used between fertilized and unfertilized plants but clipping reduced water used by 95%. Unclipped plants fertilized with 80# N/acre used more water than unfertilized unclipped plants. The amount of water required to produce a unit of a shoot was reduced 37% when fertilized. Clipping lowered this water requirement an average of 98%. Nitrogen greatly increased seed stalk numbers and the increase in shoot production due to fertilization came primarily from increased numbers of seed stalks.