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Fall 2008 We are in uncharted territory for much of agriculture in Western North America. With the prices of farm inputs at an all time high, crop commodity prices whipping up and down, and water deliveries uncertain, the same advice still applies. Use sound management decisions >more
Past Updates |
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 Managing Potassium for Organic Crop Production
An adequate K supply is essential for both organic and conventional crop production since it is involved in many plant physiological reactions. The K balance on many farms is negative, where more K is removed in harvested crops than is returned again to the soil. An overview of commonly used K fertilizer is provided. >more
 Meeting the Phosphorus Requirement on Organic Farms
Phosphorus management can be difficult in organic production since approved sources are limited. Since P is an essential nutrient, sustainable agricultural production depends on an adequate P supply. The behavior of the major sources of P for organic crop production is reviewed and an extensive list of scientific references provided. >more
 Measuring Nutrient Accumulation Rates of Potatoes — Tools for Better Management
Fertilizer can be managed more precisely when both the total nutrient demand and the daily rate of accumulation are known. Results from high-yielding potatoes in Oregon and Minnesota provide guidance for timing nutrient application to support high yields and to minimize nutrient losses. >more
 Biuret in Urea Fertilizers
In the past, urea manufacturing processes sometimes resulted in fertilizers with elevated biuret concentrations. Read more about how biuret affects plants when placed on the soil or sprayed onto leaves. >more
 Phosphite Fertilizers: What Are They? Can You Use Them? What Can They Do?
There is growing interest in including phosphite as part of a total production program. Phosphite (H3PO3) contains one less oxygen than phosphate (H3PO4), making its chemistry and behavior quite different from phosphate. Phosphite is more soluble than phosphate, making leaf and root uptake more efficient, but high concentrations are toxic for plants. Phosphite also has unique effects on plant metabolism. Phosphite supplied through the soil or foliage is slowly converted to phosphate. Soil and foliar applications are made at relatively low rates to prevent nutrition problems. For some plant species, foliar application may offer some unique benefits not seen with phosphate applications. >more
The Nature of Phosphorus in Calcareous Soils (Idaho)
Calcareous soils (containing free lime) are common in many arid and semi-arid regions of North America and occur as inclusions in more humid regions. Phosphorus (P) is very reactive with lime. Following fertilizer application, P undergoes a series of reactions that gradually reduce its solubility. In most calcareous soils, there does not appear to be a strong agronomic advantage of any particular P source when managed properly. Organic matter can inhibit P fixation reactions to some exent. Some fertilizer recommendations call for additional P to be added when the soil contains high amounts of free lime. >more
Tomato Flavor and Plant Nutrition: A Brief Review
Why don't most tomatoes purchased in the grocery stores have that same great flavor of vine-ripened tomatoes straight from the backyar garden? The answer is not simple. Here is a summary of information that helps explain the situation. >more
Humic Materials for Agriculture
Humic materials... very large and complex molecules extracted from organic matter... have been used in many ways for plant production. There are numerous reports of plant response and also of no response to these materials. This article reviews their use in agriculture anhd points to consider before using humic materials. >more
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