The Nutrition of Almonds

The Nutrition of Almonds

Contents Crop Knowledge...1 Macronutrients...2-3 Secondary Nutrients...4-5 Micronutrients...6-7 Portfolio Combinations... 8-11 Application Competence...12-13

Crop Knowledge Yara, one of the world s largest fertilizer manufacturers, has great crop nutrition knowledge created from more than 100 years of research and development. In recent years several best practice documents have been developed to consolidate Yara s agronomic expertise on many key global crops. Our trial database stores proven results from research conducted throughout the world. Following extensive research and associated field trials, the company s expertise has been brought together into a comprehensive Plantmaster publication series. In 2017 Yara will release the Nut Plantmaster as the conclusion of a joint effort with nut experts from the key world growing areas, including California. Almond Nutritional Needs Optimum tree nutrition is essential for good tree health and top nut yields. All nutrients must be available in the soil and in sufficient concentration in the tree. Good tree nutrition is similar to a good football team. Trees require 17 different nutrients, each playing its unique role in tree nutrition. A football team has different positions from wide receiver to punter and each plays a role in winning. Nitrogen and potassium are required in large amounts for good tree health while micronutrients are required in much smaller concentrations. Similarly, offensive linemen are big and strong while corner backs are fast and quick. A deficiency of a micronutrient such as zinc will reduce yield, even if all other nutrients are adequate, the same way that a team with a poor kicker is at a distinct disadvantage even if the rest of team is good. Just like each player on a football team plays a role in winning, each essential nutrient contributes to nut yield by fulfilling specific functions within the plant. APPLICATION COMPETENCE CROP KNOWLEDGE Yara Crop Nutrition PORTFOLIO COMBINATIONS Macronutrients nitrogen, phosphorus, and potassium are required in the greatest amounts. Think of them as the star players, such as the quarterback and the key running backs. They get most of the press coverage and their absence is quickly noticed. Macronutrients are the most commonly applied nutrients and trees usually receive more of them than other nutrients. Secondary nutrients are usually required in lesser amounts than macronutrients so lesser rates are usually applied. Almonds, however, take up substantial amounts of calcium. Secondary nutrients are less likely to be deficient and therefore less is usually applied. Finally, the micronutrients iron, boron, copper, iron, manganese and molybdenum are like the corner backs and safeties. They receive less attention until they miss a key tackle or leaves show deficiency symptoms then all eyes on are them. The key point is that all positions on a football team are important to winning and all nutrients are needed for top yields. Yara I 1

Macronutrients Nitrogen Nitrogen is a part of structural and functional proteins in the tree, such as DNA and RNA, and it is a component of chlorophyll, the photosynthetic factory in the leaves that converts sunlight into sugar. Less nitrogen means a smaller factory and reduced yields. Large amounts of nitrogen are taken up by the tree an average of almost 71 lbs of nitrogen per 1000 lbs of almond nuts. Thus, a 4,000 nut crop removes almost 300 lbs of nitrogen. In addition, nitrogen is incorporated into the perennial tissues, such as woody parts of the tree and roots. Lbs of N removed from orchard / 1,000 lb kernel yield 2008 2009 2010 2011 2012 Average 61.5 59.5 71.5 74.5 86.5 70.7 UC Davis study Timing of nitrogen application is important to increase the likelihood that the nitrogen is available to the tree while minimizing the potential for nitrogen to leach beyond the rooting zone. March/April May/June June/July Post-harvest ----------------- % of total N application ----------------- 20 30 30 20 Furthermore, the form of nitrogen fertilizer used can make a significant difference. Nitrate nitrogen is immediately available to tree roots while ammonium must be converted to nitrate in the soil; the speed of the biological conversion from nitrate to ammonium and resulting crop response is affected by soil temperature, moisture, ph, aeration and microbial population. Thus, if soil chemical and physical properties are not optimal for microbial activity, the conversion of nitrate to ammonium is delayed. Any residual ammonium nitrogen not converted to nitrate can promote late season vegetative growth at the expense of nut development, yield and quality. Nut trees are quite sensitive to soil acidity. Pecan seedling vigor and growth, for example, are severely limited in acidic soils when the ph is less than 6.1. Nitrification, the conversion of ammonium to nitrate in the soil, contributes to soil acidification. A long term research study at the University of California was conducted in which an almond orchard was fertilized through the drip irrigation system with different sources of nitrogen. In the harsh, acidic environment created by UAN and urea forms of nitrogen, roots will eventually become stunted and nutrient uptake by the tree will be decreased. Phosphorus Distance from Emitter (inches) 0 8 16 24 ----------------- ph ----------------- YaraLiva 5.32 6.26 6.89 7.01 UAN-32 4.85 5.00 5.35 6.13 Urea 4.01 4.69 5.02 5.84 As soil ph drops, nutrients such as calcium, magnesium and potassium may be leached through the soil profile and out of the rooting zone, with consequent accumulation of aluminum which is toxic to roots. Phosphorus contributes to better root growth and is a key component in energy production and transfer in cells. Cell membranes as well as DNA and RNA contain phosphorus. Phosphorus is mobile in the plant so deficiencies are expressed on older leaves. Phosphorus availability is reduced in cold, wet soils and this can lead to deficiency during dormancy break and early spring growth when the stage is set for top yield. 2 Yara

Potassium Trees take up large amounts of potassium, sometimes more than nitrogen, and potassium plays a key role in plant water relations and good overall plant health. 2009 2010 Average -------- lbs / 1,000 lbs nuts -------- Potassium uptake 73 83 78 Potassium is found throughout the plant but it does not become incorporated into plant structures or tissues. Deficiency symptoms are retarded growth of new leaves, and leaves that remain small and pale in color. Scorching symptoms are visible at the leaf tips and margins, and leaves are rolled upwards. Symptoms occur first in the tree tops, and in the middle of the spur. Under severe deficiency, fruiting spurs die, and yield potential of the following years will be reduced. Differences occur between the varieties in their sensitivity towards potassium deficiency. The greatest demand for potassium is in the spring with about 70% of the potassium taken up before mid-june. Leaf samples collected in July should have at least 1.6 1.8% potassium. Leaf potassium concentration ---------- % ---------- Tree potassium status < 1.0 Deficient 1.0-1.4 Insufficient 1.6-1.8 Minimum target Partial salt index of four common potassium fertilizers Partial salt index 3.0-2.5-2.0-1.5-1.0-0.5-0.0-7500 7000 6500 Potassium thiosulfate Potassium chloride Potassium nitrate Potassium sulfate Reference: Western Fertilizer Handbook, 9th Ed. A&L Great Lakes Laboratory. Recent research by Dr. Patrick Brown and his colleagues at UC-Davis demonstrated in a four-year trial that the largest almond yields were obtained when about 40% of the potassium was applied as potassium nitrate using a fanjet irrigation system. All treatments received 300 lbs N per acre as UAN solution. The UAN and potassium nitrate were applied either four times during the growing season (F) or in each irrigation (C). Both fanjet and drip irrigation were evaluated; yields were slightly less using drip irrigation Almond trees are sensitive to salts and chloride and the use of muriate of potash (potassium chloride) should be avoided, especially when low quality irrigation water is used. Potassium sulfate and potassium nitrate are the preferred potassium fertilizers because they have less salt than other potassium fertilizers. Yield (lbs/ac) 6000 5500 5000 Fanjet F = four applications of N and KN C = N and KN were applied each time the trees were irrigated SOP was applied as a surface band in February All treatments received 300 lbs of N per acre as UAN solution Drip F, 0-K F, 75KN-125 SOP C, 300KN C, 75KN, 125 SOP Yara I 3

Secondary Nutrients Calcium Calcium is the unsung hero of the tree nutrient team. Calcium is involved in many physiological functions such as cell division, cell wall integrity, water regulation and stress signaling. Adequate cell division is paramount for ensuring maximum nut fill and overall nut size, as well as promoting shoot and root elongation, especially the development of feeder roots and root hairs. Calcium is fixed in the middle lamella of cells walls and adds structure and stability. This is important in helping to provide a physical barrier against pathogens, and calcium also inhibits the enzymes produced by fungi and bacteria that degrade cell walls. In water regulation, calcium is necessary to forward the drought signal from the roots to the upper canopy of the trees which causes the stomata on the leaves to close. Adequate soluble calcium is necessary for the proper execution of all these functions and helps to ensure the production of high quality nuts. Most soils contain large amounts of total calcium, but most of the calcium is tied up in insoluble forms such as calcium carbonate or calcium sulfate and there is very little soluble calcium the only form of calcium that is available to trees. Nut trees require a continuous supply of calcium for proper root growth and stem and leaf development, although few, if any, visual symptoms of calcium deficiency appear in nut trees. Nut roots do poorly in soils with low levels of calcium. In fact, if a nitrogen fertilizer without supplemental calcium is applied to stimulate seedling growth, calcium deficiency will be magnified. This is an important factor as low available calcium can be a significant yield-limiting factor in nut production in the eastern San Joaquin Valley of California. Calcium for more dense cell structure, bigger vascular bundle diameter and less open space between the cells Microscopic analysis of orange leaves collected in a calcium field trial Magnesium Magnesium is a key component of chlorophyll and up to 20% of the magnesium in plants is found in chlorophyll. In addition, magnesium helps contribute to cell wall integrity and activates many plant enzymes. Magnesium is mobile within plants so a deficiency is evident on older tissues and is often expressed as interveinal chlorosis sometimes accompanied by upward cupping. Sulfur Low Calcium Supply High Calcium Supply Sulfur and nitrogen go hand-in-hand, and both are needed for structural and functional proteins, DNA, and RNA. Sulfur is taken up as the sulfate ion (SO 4= ) and like nitrate, sulfate can be leached from the surface soil. Most sulfur in soil is found in the organic fraction of the soil, so soils with low organic matter are more likely to exhibit sulfur deficiency. Fortunately, most almond orchards receive sufficient sulfur from the potassium sulfate used to supply potassium. 4 Yara

Micronutrients Boron Micronutrients, including zinc, boron, iron, and manganese, are needed in low concentrations by almonds, but a deficiency of any of these essential nutrients can reduce yield and affect overall tree health. In many cases, soil applications of the micronutrients are of limited value and foliar applications or combinations of soil and foliar applications are more effective. Zinc Zinc is the most commonly deficient micronutrient in the western US because it is less available in high ph soil. Zinc s primary function is synthesis of indoleacetic acid, a key plant hormone, energy metabolism and protein. Maintaining appropriate levels of zinc helps ensure a strong bud burst and subsequent crop development. Zinc is mobile within plants so a deficiency is observed in older tissues. Symptoms of zinc deficiency include decrease in stem and shoot growth, rosetting of terminal growth, interveinal chlorosis, and smaller leaves. Soil application of zinc may be effective but multiple applications are often necessary; foliar applications of zinc are often used along with soil applications. Postharvest application of foliar zinc is used to aid leaf drop while also improving zinc nutrition. Boron plays a critical role in flowering and pollination including pollen tube growth which results in greater fruit set. Higher boron levels are associated with reduced flower losses and early fruit abortion. Boron is considered immobile within the plant so deficiencies appear at the growing point such as the buds. Boron and calcium are both involved in nutrient and sugar translocation. Boron can be applied to the soil or foliage. Boron can be toxic so consult your local Certified Crop Adviser for specific recommendations. Iron Iron is essential for chlorophyll formation and enzyme activation in plants. Iron is immobile within plants so an iron deficiency is expressed by interveinal chlorosis with green veins in young leaves. Twigs die back in more severe cases and limbs or even whole trees die in severe cases of iron deficiency. Iron is less available on high ph soils or when high levels of zinc or manganese are present. Soils contain much iron, but almost all of it is unavailable to plants. Soil testing for iron is of limited value as is leaf analysis. Manganese Manganese plays a role in chlorophyll synthesis and it is a critical component in the chlorophyll molecule itself; it also is responsible for activation of plant enzymes. Availability of manganese is reduced as the soil ph increases so manganese deficiency is more common in the western U.S. because of the high ph soils. Manganese is immobile within the plant so a deficiency appears in young tissue; a deficiency appears as interveinal chlorosis on young leaves. 6 Yara

Portfolio Combinations The Yara brand sets the standard in fertilizer quality. The aim is to provide consistency from bag to bag and from year to year. All Yara products are formulated to the declaration and the analysis is guaranteed, giving confidence that What is on the label is what you get. The following almond programs are Yara s recommendation in order to get a larger almond crop. These programs will help assure a healthier crop and greater yield, which means more profitability for the farmer. APPLICATION COMPETENCE CROP KNOWLEDGE Yara Crop Nutrition PORTFOLIO COMBINATIONS For an adequate production program Almond Nutrition Program Fruit Crop Stage Bud Burst Pink Bud Flowering Petal Fall Fruit Set Hull Split Maturity Development UAN solution 30% of total N 50% of total N SOP Post Harvest 20% of total N 100% of total K 8 Yara

For a better production program Almond Nutrition Program Fruit Crop Stage Bud Burst Pink Bud Flowering Petal Fall Fruit Set Hull Split Maturity Development Post Harvest YaraLiva CN-9 30% of total N CN-9 50% of total N 20% of total N SOP 20-40% of total K 20-40% of total K Bortrac 150 1 l/ha 80% of total K YaraVita POWERBOR CA 1-2 quarts/acre BUD BUILDER 5-10 lbs/acre POWERBOR CA 1 quart/acre For a superior production program Almond Nutrition Program Fruit Crop Stage Bud Burst Pink Bud Flowering Petal Fall Fruit Set Hull Split Maturity Development Post Harvest YaraMila 15-15-15 20% of total N&K YaraLiva 30% of total N 50% of total N SOP 40% of total K KNO3 40% of total K YaraVita ZINTRAC 1 qt/acre PHOZTRAC 2-4 qts/acre BUD BUILDER 5-10 lbs/acre BUD BUILDER 5-10 lbs/acre POWERBOR CA 1 1/2-2 qts/acre ZINTRAC 1 qt/acre PHOZTRAC 2-4 qts/acre POWERBOR CA 1 1/2-2 qts/acre Soil applied products Foliar applied products Apply YaraVita foliar products as needed based on Megalab leaf tissue analysis. Potassium should be applied as potassium sulfate (K 2 SO 4 ) or potassium nitrate (KNO 3 ) to minimize the potential for chloride and salt injury. The information provided is accurate to the best of Yara s knowledge and belief. Any recommendations are meant as a guide and must be adapted to suit local conditions. Consult your local Yara agronomist for specific nutrient application rates. For more information contact your local Yara representative. Yara North America customer service Yara I 9

YaraLiva YaraVita YaraLiva is the global brand name for Yara s calcium nitrate fertilizers, including CN-8 TM, CN-9 TM, and CAN-17 TM liquid fertilizers and TROPICOTE and CALCINIT dry fertilizers. The essence of YaraLiva is quality. These calcium nitrate-based products optimize the quality of crops. YaraLiva keeps your crop healthier longer, improving shelf life, firmness, strength and the overall appearance of the crop. YaraLiva provides nitrogen and calcium that are immediately available for plants. Nitrate is the nitrogen form directly available for plant uptake. It is non-volatile and not adsorbed to soil particles, leaving it readily available to plants. YaraLiva CN-9 is the preferred nitrogen source for most horticultural and high value agricultural crops, because nitrate improves the plant uptake of the cations potassium, calcium and magnesium. The calcium from YaraLiva CN-9 improves cell wall strength and cell membrane integrity, leading to better quality, longer shelf life and increasing marketable crop yields. Greater cell wall strength and membrane integrity also help trees better tolerate stresses such as diseases, heat and cold and salinity. In addition, the calcium in YaraLiva CN-9 helps to maintain an optimum root environment for high yielding crops. YaraIiva CN-9 is the superior nitrogen fertilizer for low volume irrigation systems because it does not lower soil ph. YaraVita is the global brand name for Yara s range of micronutrients. The essence of YaraVita is attention to detail and this pays dividends when planning crop nutrition programs. Optimum crop yield and quality require application of the right micronutrient inputs at the right time. A formulated multi-nutrient product with proven and reliable performance. It s formulated for safe application at critical growth stages to satisfy crop requirements. YaraVita products recommended for the different almond crop stages: BUD BUILDER ZINTRAC CALTRAC POWERBOR CA SENIPHOS PHOZTRAC MANTRAC MAGPHOS MAGTRAC 10 Yara

YaraMila YaraMila is the name for Yara s premium fertilizers that supply nitrogen, phosphorus, and potassium. YaraMila 15-15-15 is a homogeneous fertilizer that supplies nitrogen, phosphorus, potassium, and sulfur for maximum nut yield and quality. In addition, YaraMila 15-15-15 is one of the most highly efficient sources of nitrogen, phosphorus, and potassium. Unlike a blended fertilizer, the nutrients in YaraMila 15-15-15 cannot segregate in shipping, handling, or application resulting in more uniform nutrient application and plant uptake. YaraMila 15-15-15 has a balanced nitrogen source, containing both nitrate-n and ammonium-n. A high nitrate concentration is a prerequisite to crops during rapid growth stages such as bud break, flowering, etc., while the ammonium-n is important to keep a sustained delivery of nitrogen. In addition nitrate supports the uptake on positively charged nutrients such as potassium and calcium. Compared to pure ammonium or ureabased fertilizers, YaraMila products are significantly more effective on an equal nitrogen basis resulting in higher yields and improved harvest quality. All the phosphorus in YaraMila 15-15-15 is fully plant available, as water soluble orthophosphates and ammonium citrate soluble dicalcium phosphate. The combination of different forms give greater and a longer lasting availability of phosphorus to crops over a wide range of soil types. The potassium in YaraMila 15-15-15 is important for helping the plant maintain good water relations and provides pest tolerance, and helps plants minimize environmental stresses such as frost. Potassium is essential for high yielding and high quality crops. An adequate supply of potassium has a positive effect on leaf and nut size. Finally, the potassium source in YaraMila 15-15-15 is based on sulfate of potash so YaraMila 15-15-15 contains no chloride that can injure sensitive nut crop roots. In addition, YaraMila 15-15-15 has a low salt index so it does not add excess salt to the soil. Yara I 11

Application Competence When it comes to application of products, the Justin-Time concept expresses our belief that applying the right amount of the correct product, at the time needed by the developing crop, brings the best results for growers, profits to our customers and premium positioned sales for Yara. Just-in-time helps to solve the global challenges of increasing agricultural production, optimizing the farmer s investments while minimizing the environmental impact. APPLICATION COMPETENCE CROP KNOWLEDGE Yara Crop Nutrition PORTFOLIO COMBINATIONS Megalab TM Internet based reporting system offering interpretation of soil and analysis results. Yara CheckIT TM CheckIT is an app from Yara that lets you optimize crop yield and quality through quick and easy identification of nutrient deficiencies using high resolution images. The free app offers tailored recommendations to correct deficiencies. It s available in app stores for ipad and iphone, Android and Windows phones. Fertigation Applying liquid fertilizers or water soluble fertilizers in irrigation water is fertigation. Fertigation offers the potential to increase crop yields and nutrient use efficiency while decreasing nutrient losses and helping to protect the environment because it places the nutrients in the zone with the most active root uptake of nutrients. Frequent applications of low rates of nutrients are often more efficient than a few applications of higher rates of nutrients. YaraLiva CN-9 and CAN-17 are ideal choices for applying nitrate-nitrogen and water soluble calcium to almonds. However, they should not be applied with fertilizers that contain phosphorus or sulfur because of the possibility of forming insoluble precipitates. There a few key points that must be considered when using fertiligation. The quality of the water (ph, cations, anions, salinity, potentially toxic ions, etc.) must be closely monitored to assure that insoluble precipitates are not formed when adding fertilizers to irrigation water. The nutrients should be injected into the system in the second half, or later, in the irrigation set to help assure that the nutrients remain in the root system where they are most available to the crop. 12 Yara

Yara TankmixIT Yara TankmixIT is a downloadable app that is used to check the compatibility of YaraVita micronutrients when mixed with many common crop pesticides.. TankmixIT allows better planning of spray programs and spraying opportunities with most of the YaraVita range. Each tank mix test is carried out under controlled conditions in our product development laboratories following BS EN ISO 9001:2000 guidelines and represents an accurate assessment of the performance of each mixture made. Of course, there are many variables that affect tank mixes under field conditions that can influence the mixability of any mixture made. Yara TankmixIT is just a guide, not a guarantee of either physical or biological compatibility. Yara Water Solution With water supplies and access growing scarcer in many nut growing regions of the world, agricultural solutions are needed for making the best use of water. Yara Water Solution is being validated on almonds to improve water use efficiency for this crop. This technology has successfully been used in Spain, and is applicable to all leafy plant species. The Yara Water Solution is a plant-based sensor allowing direct communication with the plant during the entire vegetative period. It provides direct information about the water status of plants using non-invasive leaf clamps (sensors) that are wired to sending units in trees. The sensitive clamps measure the turgor pressure (pressure from water within the leaf) to determine when and where water is needed. Water use and cost can be cut by up to 40% due to irrigation being applied more precisely based on the crops moisture status. This precision farming technology offers easy setting of irrigation thresholds to prevent over irrigation which can lead to plant diseases and movement of mobile nutrients out of the root zone and into groundwater. Proper alignment of water use to crop needs will help to maximize the use of this scarce resource. Yara I 13

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