Salinity poses a significant challenge to almond growers in certain areas and can greatly impact the performance of an orchard over time, costing producers in lost income. According to Mae Culumber, nut crop advisor from the University of California Cooperative Extension, almond trees are salt-sensitive and understanding soil salt levels and water sources become crucial even before planting an orchard.
There are two types of salt stress that impact almond trees -- osmotic stress and specific iron toxicity. "It's important to know the type of problem that you're dealing with, particularly when you have a change in water source, to know what the composition of salts is,” Culumber said.
Osmotic stress arises from salt accumulation, hampering water and nutrient uptake, leading to reduced vigor and early yield loss. If salt accumulates over time, specific iron toxicity becomes evident, causing the tree to absorb salts and accumulate in the roots, resulting in necrotic leaves. This damages the tree's ability to photosynthesize and nourish developing kernels.
Culumber said maintaining a balance between salinity and amendments is essential and regular soil sampling helps decide between water or soil applied amendments. “Annual sampling is recommended for the soil, and we want to sample at both depth and the top zero to three inches,” Culumber said. “That will help us decide whether or not we're going to use water applied or soil applied amendments."
