Effects of Boron Fertilizer and Water Regimes on Alfalfa Yield and Quality

Objective:                   

To evaluate the effects of boron fertilizer rate and irrigation application on alfalfa yield and quality.

Personnel:                  

J.A. Torrion, R.N Stougaard, E. Glunk, E. Sapkota, J. Garner

Summary:       

Boron treatments were applied at five rates detailed in Table 1. Three water use treatments were applied as the main factor, which included rainfed, half or deficit irrigation (50% ET), and sufficient or full irrigation (100% ET). The experimental design was a split plot with four replications. There was a full soil profile at the beginning of green up in spring as rainfall received in the fall and early spring was above average. Supplemental irrigation was applied when 35 percent of plant available water was used up. Rainfall events and amounts of irrigation applied per treatment are shown in Figure 1. Height measurements were taken prior to cutting when plants averaged 10% flowering. Two cuttings were made.

No significant differences were observed in height or yield data from boron fertilizer treatments (Table 3). Significant differences were observed for height and yield from water treatments (Table 4). The highest yield for total harvest was 2.16 T/A for 50 ET which was equivalent to the 100ET. This implies that the 50ET treatment did not impact yield as it allowed to store rainfall more efficiently (i.e., 60 DAE rainfall in Figure 1). Significant differences were observed for all but two nutrient analysis for hay quality from boron treatments for first harvest, but none for second harvest (Table 5). No significant differences were observed for hay quality from water treatments for first harvest, but significant differences were observed for second harvest (Table 6).

Figure 1. Rainfall events and irrigation applied per treatment.