Root Biology: Nitrogen & Water Utilization: Leo Lombardini

Pecan Root Biology Linked to Nitrogen and Water Utilization

Leonardo Lombardini & Astrid Volder

This component of the project involves developing an understanding of the timing of root activity, and characterizing nitrogen and water movement through the soil profile. In addition, the absorption of nitrogen and water by roots is under study.

Pecan Studies

Nitrogen application is an essential horticultural practice for optimal tree growth and profitable pecan production. To ensure productivity and crop quality, N is applied in the largest amounts.There is little information that validates the current recommendations with root development and whole-plant physiology. We believe that new strategies are necessary to improve the efficiency of nitrogen application. However, lack of below ground data hampers our understanding of the processes governing the cycling and utilization of N. Knowing when the roots are active, and when applied nitrogen is absorbed by roots is crucial to develop improved management practice.

Regarding irrigation practice, Most small- to mid-size pecan growers still base their irrigation schedule on intuition or calendar days.

Goals of this study include targeting applications of water and nitrogen to the periods of maximal root activity and plant needs, minimizing the detrimental effects caused by nitrogen application and water misuse, and sustaining and efficiently using land resources in production through improved management systems.

Specific research objectives for this study include:

• Determine the pattern of fine root production in establishing Pecan trees
• Trace the uptake of nitrogen in Pecan trees and establish a possible linkage with new root production
• Determine whether nitrogen application rate interacts with root production and possibly efficiency of nitrogen uptake
• Link root production rate to aboveground growth, physiology and phenology