What are crop nutrient requirements?
Nutrient management is critical in increasing or maintaining crop yields on a single parcel of agricultural land. To meet crop needs throughout a growing season soil fertility must be consistently high, which can be attributed to the presence and availability of nutrients. There are fourteen nutrients that are supplied to crops from soil and fertilizer sources. Of these, 6 are widely considered macronutrients, while the rest are micronutrients. Macronutrients are used in relatively larger amounts by the plant, however micronutrient deficiencies can be equally damaging to yield and profitability. For more information on the essential nutrients for crop growth see the Crop Nutrient Requirements Focus Topic.
Determine your need
Perform a soil test
Perform a tissue analysis
- Plant Tissue Sampling
- Plant Tissue Sampling in Orchards and Vineyards
- Corn stalk nitrate test Growers of grain and silage corn can assess if they are over- or under-fertilizing their fields using this test. When performed over a series of years and combined with yield information, this test can help growers to become familiar with whether their nitrogen applications exceed what is needed for optimal yields or whether they are not applying enough nitrogen. Sampling can be done any time between 1/4 milk line, which is just before harvest, to about 3 weeks after black layer.
Check your symptoms
- Guide to Symptoms of Plant Nutrient Deficiencies
- Nutrient Deficiencies and Application Injuries in Field Crops
Consider other factors
Water
- Self-Evaluation Techniques: Evaluating Water Quality
- California Agricultural Water Stewardship Initiative's Nutrient Management: an overview of nutrient and irrigation management
Soil pH
- International Plant Nutrition Institute Soil pH and the Availability of Plant Nutrients
- University of Illinois Extension Managing Soil pH and Crop Nutrients
- USDA Natural Resources Conservation Service Soil Quality Kit - Soil pH: this guide for educators can be useful interpreting the results of soil pH tests
Nutrient losses
- USDA Natural Resources Conservation Service Crop Nutrient Tool: this tool is useful in calculating the approximate amount of nitrogen, phosphorus, and potassium removed from the field with harvest
Know your nutrient
Nitrogen
Phosphorous
- Rice Phosphorus Fertilizer Budget and Application calculator
- PennState Extension Managing Phosphorus for Crop Production
Potassium
Secondary Nutrients
- Secondary Plant Nutrients: Calcium (Ca), Magnesium (Mg), and Sulfur (S)
- Soil Health Nexus Sulfur, Calcium and Magnesium
Micronutrients
- University of Arizona Extension Guide to Symptoms of Plant Nutrient Deficiencies
University of California nitrogen fertilizer guidelines for selected crops
Due to the variety of field, farm, and regional factors affecting plant nutrient requirements, it is impossible to prescribe specific and broadly applicable recommendations for fertilization rates. The following table provides general guidelines for specific crops, developed by University of California researchers. Numbered publications can be found in the UC Agriculture and Natural Resources catalog.
Nitrogen Guidelines (lbs/acre)
| Crop | Minimum | Maximum | Source |
Alfalfa | 0 | 50 | Summers and Putnam 2008 (Pub #3512) |
| Almond | 100 | 200 | Micke 1996 (Pub #3364) |
| Avocado | 67 | 100 | Faber et al. 2011 (Pub #3436), Lovatt 2001, Wolstenholme 2004 |
| Bean, dry | 86 | 116 | Long et al. 2010 (Pub #8402) |
| Broccoli | 100 | 200 | LeStrange et al. 2010 (Pub # 7211) |
| Carrot | 100 | 250 | Nunez et al. 2008 (Pub #7226) |
| Celery | 200 | 275 | Daugovish et al. 2008 (Pub #7220) |
| Corn | 150 | 275 | |
| Corn, sweet | 100 | 200 | Smith et al. 1997 (Pub #7223) |
| Cotton | 100 | 200 | Hake et al. 1996 (Pub #3352) |
| Environment horticulture | Newman 2009 (Pub #3508) | ||
| Grape, raisin | 20 | 60 | Christensen 2000 (Pub #3393) |
| Lawn(Heavy soil) | 174 | 261 | Harivandi and Gibeault 1997 (Pub #7227) |
| Lawn(Shade) | 87 | 130 | Harivandi and Gibeault 1996 (Pub #7214) |
| Lemon | Ingels et al. 1994 (Pub #21521) | ||
| Lettuce | 170 | 220 | Turini 2011 (Pub #7215), Smith et al. 2011c (Pub #7216) |
| Melon, cantaloupe | 80 | 150 | Hartz et al. 2008 (Pub #7218) |
| Melon, watermelon | 160 | Baameur et al. 2009 (Pub #7213) | |
| Melons (mixed) | 100 | 150 | Mayberry et al. 1996 (Pub #7209) |
| Nectarine | 100 | 150 | Strand 1999 (Pub #3389) |
| Oats | 50 | 120 | Munier et al. 2006 (Pub #8167) |
| Onion | 100 | 400 | Smith et al. 2011b (Pub #7242) |
| Oranges | Ingels et al. 1994 (Pub #21521) | ||
| Peach, cling | 50 | 100 | Norton et al. 2007 (Pub #8276) |
| Peach, free | 50 | 100 | Norton et al. 2009 (Pub #8358) |
| Pepper, bell | 180 | 240 | Hartz et al. 2008 (Pub #7217) |
| Pepper, chili | 150 | 200 | Smith et al. 2011a (Pub #7244) |
| Pistachios | 100 | 225 | Beede et al. 2005 |
| Plums, dried (prunes) | 100 | Norton et al. 2007 (Pub #8264) | |
| Plums, fresh | 110 | 150 | La Rue and Johnson 1989 (Pub #3331) |
| Potato | Strand et al. 2006. Pub. #3316. | ||
| Rice | 110 | 145 | Mutters and Thompson 2009 (Pub #3514) |
| Safflower | 100 | 150 | Kafka and Kearney 1998 (Pub #21565) |
| Strawberry | 150 | 300 | Strand et al. 2008 (Pub #3351) |
| Tomatoes, fresh market | 125 | 350 | Le Strange et al. 2000 (Pub #8017) |
| Tomatoes, processing | 100 | 150 | Hartz et al. 2008 (Pub #7228) |
| Walnuts | 150 | 200 | Anderson 2006 (Pub #21623) & Ramos 1997 (Pub. #3373) |
| Wheat | 100 | 240 | Munier et al. 2006 (Pub #8167) |
The above table was adapted from the California Nitrogen Assessment (2016).
The application of any fertilizer or soil amendment should be consistent with the "4 R's" of nutrient management. The "Fertilizer Nitrogen" focus topic provides more details on proper application of soil amendments.