Almond Series #3

This is the third in a series of blog posts about a trial we established in 2019 on a few almond farms in California. The original grower is now only using the biological program on his orchards. Without controls we cannot make data comparisons between treatments. However, the fields continue to improve in biological health while historical yields have been maintained. 

With a 50% reduction of fertilizers and pest sprays we’ve seen a large-scale reduction of Alternaria and Hull Rot and complete elimination in some areas. Alternaria is a fungus that causes leaf spots in almond trees. When severe trees can be almost completely defoliated. Hull Rot is caused by another fungus that affects the hull and eventually the fruit. This holds true with one of the basic tenets of soil health.  As the diversity and health of beneficial microbes goes up, disease pressure should go down.  It also can help to directly apply beneficial biology foliarly until the soil can catch up. The water holding capacity of the soil also continues to improve. 

The fields with cover crops are experiencing the fastest and most significant improvements in both soil and tree health, along with significant increases in phosphate, potassium, and calcium levels. 

The second grower, whose 2020 treatment was their standard program with the addition of Earthfort’s Provide and Revive at 1 gal/lb each month for six months, revised the treatment for 2021 by increasing the application rate to 2 gal/lb per acre in February, April, and October. Provide is a biological inoculant containing a highly diverse and abundant spectrum of soil life, and Revive is a food source for the soil life that helps to increase activity levels, especially for the generally limiting fungi. The treatment program was also revised in 2021 to eliminate synthetic nitrates and use sap analysis to fertilize with precision only when needed. Fertilizer rates were reduced by 50%. 

This year all three treated blocks had 15+% per acre yield increases (from 2600 lbs per acre to 3000 lbs per acre) and utilization improvements from 26% to 30%. Utilization, also called ‘turnout,’ is the percentage of harvested weight that is actually edible nut. 30% utilization is a significant figure in the almond industry. When looking at these two metrics together (2600 lbs per acre x 26% utilization, and 3000 lbs per acre x 30% utilization) the difference between treated and untreated blocks is pretty drastic. The treated sections produced 900 lbs per acre of edible nut while the untreated sections produced 676 lbs per acre - that is a 28% difference in true yield! These orchards had never reached yields as large as these and their adjacent controls remained at the lower level, producing 2600 lbs per acre with 26% utilization.

This trial has been so successful that this grower is expanding from 240 acres to 6800 acres on the program.


Jerel Kratt, our partner at Regenerative Crop Consulting who has led these trials, believes the reason Treatment E was so successful in 2021 is due to four factors. 

  1. The increased rate of Provide and Revive applied during the reproductive phases of the tree augmented productivity

  2. Eliminating synthetic nitrate and phosphate, and fertilizing with a biologically-friendly fertilizer blend at low rates only after crop set improved biology in the soil 

  3. Adding Molybdenum to the nitrogen fertilizer for enhanced nitrate reductase enzymatic activity

  4. Using Plant Sap analysis for more precise soil and foliar fertilizer applications

Jerel concludes that “the result of three years of trials show that Provide and Revive are effective at improving soil and tree health, and when applied at correct timings and rates with the correct fertility, can have significant improvements in yields, utilization percent, and reduction of synthetic inputs.”