Inquiry from Alfalfa Grower


If I want to make 12 tons of alfalfa, how many lbs of K and P do I need to apply?

Thanks, Alfalfa Grower

Dear Alfalfa Grower:

That is an easy and difficult question to answer.

Here is the easy answer: Alfalfa removes 9 lbs of P2O5 and 60 lbs K20 per ton of 90% dry matter produced. So, doing the simple math, in a perfect world, one will need to apply 108 lbs P2O5/ac and 780 lbs of K2O/ac.

The difficult part is to estimate the amount of P and K already present.

1. Our soils are relatively young geologically speaking. Soil minerals contain P and K occur naturally in our soils. Basically soil nutrients come in and out of plant availability. Plant availability of nutrients in the soil depends upon the soil chemistry. This is influenced by a number of factors: micro-organism activity, aeration, soil moisture, pH, soil texture, water quality, lime content of soil, root growth.
2. Higher yielding crops remove more nutrients from the soil.
3. Organic Matter from previous crops contribute to more nutrients in the soil.
4. Fertilizer applications contribute nutrients in the soil.

I have a library of books on this subject, but the answer is to monitor the soil P and K on a routine basis. Follow the applications of fertilizers’ to see the responses. Make up the differences to maintain high amounts of P and K in the soil so that will not limit yields.

Thanks, AQ

Aron A. Quist, CPAg/SS
Stanworth Consultants
cell 760-427-0941



Stanworth Consultants is conducting a replicated experiment to analyze the potential effects on soil chemistry by the use of applications of large amounts of beet lime on calcareous soils. A replicated experiment is now underway with 4 treatments of different phosphorus fertilizer types including an untreated check. The plots are split with an application of beet lime on one half and none on the other replications.

Crop grown is durum wheat.

Soil Columns with soil moisture sensors on left.

Irrigations on the columns are being predicated upon by Echo soil moisture sensor data.


Chemical analysis of plants and soils and yields will be measured at season end. Reports will follow.



AWANA is a children’s ministry that is based upon learning about a loving God by studying His word.   The children memorize  scripture, play games and earn points for other activities.    It is based upon 2nd Timothy 2:15. Which encourages children (Clubbers)  to study hard, be good workers and think critically about scriptures in the bible and ponder them.

Cubbers Range in age from Kindergarten to High School.

Awards night.

Clubbers earn points by passing sections that teach them about God’s Word.   They earn points (awana bucks) that accumulate through the year.   These AWANA bucks can be spent at the AWANA store.   Many children save these bucks and purchase Christmas gifts for their family members.

Balloon Pop Game

It’s not ALL fun and games,  but a good portion is.   The games accomplish a number of things.  1. is to help them shake off pent up energy,  this allows them to concentrate on studies, 2. it helps them to develop a team spirit and 3. it helps build relationships and shared experience.

Drive In Movie Theme Night

Club night is made more fun by having theme nights.    “Movie Night” is made a little different by making cars to sit in during the movie showing.

Pie in the Face Night

Clubbers are encouraged to work hard on their sections.   Section point winners can throw a pie in the face of their selected Leader.    Sometimes the leaders can put the pie in the face of the Clubber!

2011 Trek trip to Joshua Tree.

Clubbers are encouraged to explore God’s World.   The AWANA program is designed to equip kids to experience a life that contains His joy supported by the word of God.



Stanworth Consultants supports Science Curriculum at Local Elementary Schools

Max Kalakosky Discusses Soil Salinity

Last year Stanworth Consultants participated in Science Education Outreach Project at local schools.

Max Kalakosky, Chemist at Stanworth Lab helped children understand how soil quality can affect plant growth and the establishment of habitat plants.


Students Taking Soil Samples


Soil samples were taken of the proposed habitat area, the samples were extracted and analyzed for salinity. Determination of how these results would impact the restoration of native plants was discussed.


Analysis of Samples

The students learned how chemistry can be used to help improve the environment and grow plants more successfully.

Stanworth Consultants volunteered to participate in this Science Grant project coordinated by Jesse Yonkovich for the PVUSD.   Many thanks for his efforts to support our students technical foundations.


Posts from the Archive: The Goal and Objectives of Good Irrigation Management.

Sometimes you stumble on some old work and say,  wow did I write that?   Below are some thoughts on the benefits of good irrigation scheduling.

Perhaps the most misunderstood, over looked, and under utilized practice in crop production systems today is proper irrigation scheduling; it encompasses the most critical input, water. Water is the catalyst for many phyto-chemical reactions within the plant that are necessary for the plant to obtain optimal health.  Below is the rational and legitimacy of irrigation scheduling.


Irrigation scheduling should be utilized as a mechanism to respect the water consumption needs of plants through their various growth and developmental stages in order to attain high yields while maintaining soil quality and conservation of water.


  1. Target soil moisture depletion percentages should be utilized by to schedule the irrigation of fields.
  2. The “feel” method and other technologies should be used to properly monitor soil depletion levels.
  3. The calculation of moisture loss should be equated by utilizing evapo-transpiration in accordance with the modified penman equation and crop coefficients.
  4. Improve uniformity of irrigation applications by calculating flow rates and application efficiencies of the irrigation system being utilized.
  5. Influences such as moisture holding capacity, knowledge of the plant root depth, soil texture, salinity, and organic matter should be considered when determining plant available water.
  6. Improve soil absorption and pecolation efficiencies in order to properly leach accumulated salts through, and past, the root-zone profile by properly quantifying the target moisture level in the root profile and the amount of water to be applied.
  7. Critical growth stages should be considered and irrigation should be utilized to improve crop quality.
  8. Mitigation of ground water pollution from fertilizers by increasing plant root depth and allowing proper moisture transport through the soil profile and optimizing nutrient management.

 Proper irrigation scheduling is vital in order to optimize plant and soil interactions.  Water plays important roles in many facets of not only plant health, but also in soil fertility.  That being the case, quantifying the amount of water and the time between irrigations has a direct affect in the quality of a crop.


Alfalfa Irrigation, the last kiss before the cutting.

Good alfalfa production depends on good irrigation scheduling in the desert.   The most critical irrigation is the one prior to the cutting.  Fields that lack sufficient water for good regrowth after the cutting suffer significant yield losses.    Each day a cutting is delayed after an irrigation is worth 4 days in the windrow for curing (1.4 Kc vs 0.3 Kc).    Below is a table to assist local growers in estimating the minimum time needed for the soil to be sufficiently dry to swath the field.


Cutting Trends in Desert Alfalfa to achieve 10 tons/ac.

Are your fields producing 10 tons/ac per year of alfalfa hay?    If not, the cutting data above may give you an hint as to why.

Many years of research here in the Palo Verde Valley, California on good producing alfalfa has shown us that good fields follow a yield trend through the season.    Our highest yielding cutting generally is the 5th cutting (May-June) at 1.61 tons/ac.   Yields diminish from there to the end of the season.

It has been our experience that if the third cutting out yields the second cutting then the field may be on it’s way to 12-13 tons/ac for that year.


Responses of Alfalfa Production and Quality to Water run applications of Micro-organisms.

Below is an excerpt from Stanworth Crop Consultants Inc Research

Introduction: Questions regarding soil health in the SW deserts of the United States have been posed. Indigenous populations of micro-organisms may not be as effective in decomposition of organic matter or competitive with plant parasitic nematodes or soil borne diseases. Recent regulatory and environmental pressures have been put to growers to switch from caustic soil sterilants (methyl bromide) to alternatives. These alternatives include biological organisms as agents to help control soil borne diseases. Recently, benefits of these materials have been noted anecdotally. Increase in production and quality have been seen in treated versus untreated fields. Increase in plant analysis nutrients, primarily nitrogen and phosphorus have been observed on sugar beets. Decreases in nematode populations have been seen in treated vs untreated fields. A replicated treatment and untreated control experiment was proposed. This experiment was performed to test the efficacy of using Pure Ag Solutions micro-organisms and quantify benefits on nutrients, yields and quality of alfalfa hay.

Results: Alfalfa quality improved significantly in the treated plots. Median %ADF and %NDF decreased over 3% in treated versus untreated check plots. Energy calculations showed an increase in median Relative Feed Value from 119 to 133, TDN increased from 53.7 to 56.1. Median Crude protein increased over 1% in treated plots over the untreated check, but was not statistically significant. Yields increases were noted. Average yields of the treated plots were 1.23 tons/ac, the untreated plots averaged 1.09 tons/ac. This was not statistically significant however. Total bale counts showed there was no increase in yield, treated 1.46 tons/ac, untreated plots at 1.47 tons/ac. Bale weights were estimated at 105 lbs/bale. Comparison of soil nutrients between treatments revealed that there was no significant change in any of the soil nutrient tested in alfalfa soils treated with Pure Ag Solutions Micro-organism when compared to controls. Alfalfa plant tissue analysis of the top 6” of plants showed a similar lack of significant differences in nutrient content between treatments.

Discussion: Significant increases in alfalfa feed quality and moisture was noted in the treated over the untreated check of these fields. The mechanism of this increase is unknown. Increase in alfalfa leafiness, or higher leaf to stem ratio may be occurring in the treated areas. Possible influences from micro-organisms could be better tilthe and aeration of the soil allowing better uptake of water to the plants, giving more lush leafy growth. This experiment was performed during the peak of the desert summer. High heat stress on alfalfa causes a condition locally described as “summer slump”. Alfalfa quality and yields are depressed as plants struggle to survive through the heat. I recommend checking the same plots again in the fall as cool temperatures and un-stressed plants may respond in the treated plots.


Undersander, Dan., et al. Forage Analysis Procedures. Omaha Ne.: National Forage Testing Association. July 1993

Zar, Jerrold H. Biostatistical Analysis. Englewood Cliffs N. J.: Prentice-Hall Inc. 1974

Pure Ag:

Yield Estimate: