End of Year Expense Considerations

At this time of the year, many farmers are looking through the books and realizing the financial return of their orchard operations. With a profit, money can be spent on orchard improvements and equipment, which often have tax saving benefits.  In the case of a negative return, operations should be reviewed and a strategy should be developed and implemented to make the orchard profitable. Regardless of returns, the following should be considered to help make orchard operations run more efficiently for next (and future) seasons.

November 22, 2013

Sustainable Nutrient Management: a Review.

Almond harvest looks to be progressing well (knock, knock).  Orchard fertility/nutrition planning for the 2014 is beginning.  Now is a good opportunity to review the basics of almond orchard nutrient management.  While some of what follows will be review for many readers, a quick review may be of value. Sustainable nutrient management comes down to the four R’s – the Right Rate, the Right Time, the Right Place, and the Right Material.  A sustainable approach to orchard nutrition is intended to optimize crop production and maximizing net profit while reducing the risk of environmental contamination.

September 9, 2013

Postharvest Fertilization – Q&A

Q. How much nitrogen should be applied in the postharvest period? A. This depends.  This should be based upon the current tissue N levels detected from mid-July sampling. If within the prescribed ranges of leaf N (2.2-2.5%), 20% of the budget should be planned for application. If richer (>2.5%), slightly less can be added. If really high N leaf levels are observed (>3.0% in mid-July), postharvest fertigation may not be needed. 

August 17, 2013

Nutrient Removal for Almond

I have received a few inquiries about the nutrients removed for almond. Based on Dr. Patrick Brown’s group’s work (Sebastian Saa Silva and others), the amount of NPK removed with every 1000 kernel pounds of almond is: Nitrogen – 65 lbs, Phosphorous – 8 lbs, and Potassium – 76 lbs. This includes the nutrients removed will all of the materials exported out of the orchard in a typical pick-up operation – hulls, sticks, leaves, shells, and kernels. Keep in mind that more than the above amounts may be needed to compensate for the inefficiencies of application and uptake (i.e. nitrogen uptake efficiency is somewhere between 75-85%, condition dependent — so to have 65 lbs of uptake, 76-85 lbs of N must be applied). As noted in the comments below, potassium and phosphorous must be converted to oxides. This can be done as follows: Almond removal 8lbs of P = 18.4lb of P2O5 76 lbs of K = 91.2 lbs of K2O For Phosphorus o Lbs. P x 2.3 = lbs. P2O5 o Lbs. P2O5 x 0.43 = lbs. P   For Potash o Lbs. K x 1.2 = lbs. K20 o Lbs. K20 x 0.83 = lbs. K

January 24, 2013

Fall Foliar Fertilizers: Targeted v/s General Approach

A PCA asking me the other day what I thought of a general micronutrient (iron + molybdenum + zinc + copper + manganese + boron +?) compared to a standard zinc + boron spray program that is common in postharvest almonds in the areas where I work. This question got me thinking about a review of fall fertilizer programs in general, with a focus on foliar nutrients. There are more than a dozen mineral nutrients essential for plant growth. However, only a handful of those nutrients have been shown to be important – in general — to profitable almond production. These

September 19, 2012

Summer leaf sampling is serious business

It’s July. Among key orchard activities as harvest approaches, it’s time to sample almond leaves for nutrient analysis. The lab analysis report for a leaf sample serves as part of the “report card” for your fertility program for this growing season for a particular variety in a particular block. A previous post from “The Almond Doctor” covers the practice of summer leaf sampling and shows the University of California critical nutrient levels for almond leaves sampled in July. This post will talk about several additional steps to orchard nutrition assessment in summer and to stress the importance of these practices to the commercial success of an orchard. Take separate leaf samples for each variety in a block. Crop load is the key factor determining mature almond tree nitrogen (N) and potassium (K) use. Different almond varieties in the same block can produce different yields and nutrient demand based on their genetic potential and conditions at bloom. If you don’t already, consider taking leaf samples for nutrient analysis from each variety. Use the lab reports and crop yield reports from each variety in the block from this year as background information when it comes time to apply N and/or K fertilizer for next year. If you applied the same amount of N and K fertilizer this season to all trees in an orchard, yet the Non-pareil yield was off and the Monterey yield was high, can you see that reflected in the leaf analysis reports? Variety specific leaf analysis and cropload data can help you understand how different varieties use expensive nutrients and how you might possibly fine tune your fertilizer delivery to optimize yield without wasting money.  Look up between leaf samples. Adequate tree vigor (growth) is key to good production. Adequate leaf nutrient levels and little to no growth

July 18, 2012

Varietal Bloom Issues

Weak bloom experienced in an orchard:Nonpareil and Monterrey shown. I have received more calls about weak bloom on almond pollinators. These trees have low counts of fruit bud, and the vegetative buds have pushed giving the tree a green instead of white appearance. The reports have been coming in from orchards of “juvenile orchards” (7-10 years of age), which typically have yielded quite heavy for their age. Nonpareil is affected, but the later harvested varieties, which include Monterrey and Fritz, are affected more severely.   In being in these orchards, it is clear that the period of fruit bud development was affected sometime last year. Fruit bud development/floral initiation varies among varieties. Studies have shown that ‘Nonpareil’s’ fruit bud differentiates about 7-14 days after harvest, while other varieties, such as ‘Carmel’, the majority of fruit buds differentiate prior to ‘Carmel’ harvest. This timing will be delayed in cool, mild years. Tree stressed imposed during this period will reduce fruit bud set, and the buds will remain vegetative (leaf buds). Very fruit bud are found on the trees,the majority of the buds are vegetative (leaf). In regards to the weak bloom, working with the farmers, we were able to identify some of the possible stressors that may have occurred during the period of fruit bud differentiation. Although we are unsure of the exact problem(s), the ones we are considering include:1. Holding back of irrigation in order to “force” hull-split or harvest,2. Excessive foliar disease, including rust or scab, that caused defoliation,3. Improper nutrient management – usually very low potassium and boron, and 4. heavy yields that reduced the vigor of the tree, impacting growth and the number of fruiting spurs available for future crops. In many cases, more than one of these issues could have affected the orchard. In orchards that experienced defoliation to foliar disease, many

March 2, 2012

Compost Applications for the Almond Orchard

Compost is applied by many growers as a supplement to their nutrient management program. Composts may contain nitrogen, phosphorous, potassium, and other micro-nutrients. Applications of compost also add organic matter, and the associated organic acids, which has been shown to increase soil tilth in cropping systems.  Since all composts vary in nutrient content due to the variability in source material, nutrient benefits can only be determined through analysis. Nitrogen from Compost. To understand the effect of nitrogen from compost, we must first understand the nitrogen cycle. Organic matter contains nitrogen that is bound to various chemical compounds within the plant material. Termed organic nitrogen, it is unavailable to the plant. It can only be made available to the plant upon mineralization and conversion to nitrate through the process of nitrification. These processes are mediated by the soil microbial community. Once converted to nitrate, the nitrogen is available for plant use. Synthetic fertilizers go through similar processes depending upon their starting point (i.e. ammonium, nitrate, etc.). Figure source: www.physicalgeography.net/fundamentals/9s.html Most finished composts vary from 0.5-2.5% total nitrogen. Since most of the nitrogen is held within plant compounds (organic form), not all of the nitrogen will be mineralized and available upon application. Research by Dr. Tim Hartz, UC Davis, has shown that most composts only release about 5-10% of the nitrogen in the nitrate form. Composts that have a lower carbon to nitrogen ratio release nitrate on the higher end of this range. Higher nitrogen containing composts (> 3% nitrogen) may release more than 10% of the nitrogen. Nitrogen benefits from compost also appear to be reduced in the following growing seasons, with very little mineralization occurring. At this point, it appears that the compost is simply organic matter. Phosphorus from Compost. Phosphorous (P) content within compost can be significant. Since exportation of

November 6, 2011

Compost Quality: What the Analysis Reveals

Compost is applied by many growers as a supplement to their nutrient management program. Adding organic matter and the associated organic acids, has been shown to increase soil tilth in cropping systems. All composts vary in nutrient content, which is heavily dependent upon the source material of the compost. Since sources vary, it is important to have an analysis in order to determine nutrient content. To understand how compost works, we must first understand the nitrogen cycle. Organic matter contains nitrogen that is bound to various chemical compounds within the plant material. Termed organic nitrogen, it is unavailable to the plant. It can only be made available to the plant upon mineralization and conversion to nitrate through the process of nitrification. These processes are mediated by the soil microbial community. Once converted to nitrate, the nitrogen is available for plant use. Synthetic fertilizers go through similar processes depending upon their starting point (i.e. ammonium, nitrate, etc.). Nitrogen from Compost.Most finish composts vary from 0.5-2.5% total nitrogen. Since most of the nitrogen is held within plant compounds (organic form), not all of the nitrogen will be available upon application. Research by Dr. Tim Hartz, UC Davis, has shown that most composts only release about 5-10% of the nitrogen. Composts that have a lower carbon to nitrogen ration release on the higher end of this range.Higher nitrogen containing composts (>3% nitrogen) may release more than 10% of the nitrogen.. Nitrogen benefits from compost also appear to be reduced in the following growing seasons, with very little mineralization occurring. At this point, it appears that the compost is simply organic matter. Phosphorous from Compost.Phosphorous (P) content within compost can be significant. Since exportation of P from the almond orchard is low (7 lbs/1000 kernel lbs), attention should paid to prevent over application of P. P is

November 5, 2011

Fertilizing Young Almond Trees – A Few Tips

A few questions come up every year in regards to fertilizing first, second, and third leaf trees. Since these trees are rapid growing, and in some cases, producing crop, adequate fertilization is crucial for growth. First leaf trees: As a guideline, I generally recommend no more than one ounce of elemental nitrogen per tree per application. Three to four (or more) applications using a general blend (i.e. 12-12-12 NPK) fertilizer per year will produce a nice result. Using a triple 12, this totals about 8 ounces of actual fertilizer applied per tree.  Applications should begin upon leaf out and continue about every 4-6 weeks.  To prevent any nitrogen burn, the first applications of the year should be less than one ounce while later applications should not be greater than one ounce. Although I know some growers are successful, I have observed enough tree damage to caution against using liquid based fertigation products for first leaf trees. It is easy to overdose the trees with nitrogen, especially in hot weather, causing tree die-back. I agree that using granular fertilizers is a conservative approach, but one that has been tested and used extensively over the years. Second leaf trees: The rootzone of 2nd leaf trees can be quite extensive, but is still limited in comparison to mature trees. Even if the grower is able to fertigate, I usually still like to see the first application to be granular. Why? In many cases adequate potassium and phosphate have not been applied in the previous dormant season, thus applying a 12-12-12 fertilizer will ensure at least some level of these nutrients as the tree begins the rapid growth period of April and May. Later applications can be made through the fertigation system. Again, follow the rule of one ounce per tree per year of growth. So,

March 25, 2011