Friday, December 23, 2011

Kitchen Table and Rainy Days

We are a small business consisting of three people with lots of ideas. To put all those ideas into some form of direction takes planning. That is what we did two days in November and December. The kitchen table was just the right size for three people, papers, note pads and beverages.

It is amazing how a small business can come up with so many ideas. We focused mostly on sales and products. However we also shifted into the abstract: what is the plan if a key person dies or becomes incapacitated? This is not unlike the decisions farmers have to make from time to time.

I think the most invigorating feeling that I got from this round table meeting was the need to go forward. We want to get better at what we do. We want to focus on the ag market and the turf market bringing to both the best information, knowledge, and products that we can find to help our customers move forward with success. Yup it was a good day around the kitchen table and we look forward to implementing our ideas in the year ahead.

Monday, November 7, 2011

Rhizosphere Interactions

OK so you have had soil tests pulled, and fertilized accordingly to prepare for planting. Your background or bulk soil nutrition is where you need it to have a successful crop – weather permitting. You saved money and time by only using the type and amount of fertilizer needed.
So why do some crops fail to establish themselves and take off with vigorous growth? This question has many answers we hear all of the time but don’t pay much attention to. Solubility, availability, nutrient mobility in the soil, and the health and activity of the microbial populations in the soil are a few pieces of the puzzle.

We need to look specifically at the roots and the soil around and near the root zone also called the rhizosphere. This area of soil to root contact is where the action is.

Let’s look at solubility, availability, and we can’t forget the resource that is always running short - TIME. It takes time for that pre-plant fertilizer to dissolve into the soil solution and wind up in the right form for uptake by the crop. If the microbial populations in the soil are not diverse enough it could take even more time to access those nutrients. If it is cold and dry it could take even longer!

I would like to use phosphate as an example and I won’t dwell too long on the pH connection to phosphate availability. I will just mention that phosphate availability is more drastically reduced at the following pH values: pH 3-4 when it likes to tie up with iron, pH 5-6 when plentiful aluminum is the problem, and pH 7-8 when calcium can get in the way. Phosphate exists in two forms – orthophosphate and polyphosphate. Plants take up the orthophosphate ion and it takes time for the polyphosphate to convert to orthophosphate. It can take up to 30 days to convert only half of a polyphosphate fertilizer to orthophosphate. What’s my point? Despite your commendable soil testing and responsible fertilization – there can be gaps in nutrient availability that can lower yields and quality.

Avoid nutrient availability gaps. Use starter fertilizers with highly available nutrients placed in and near the root zone or where the roots will be very soon.

Your crop is not just sitting there idly waiting for the good stuff to come to it. Those plants can help themselves to an extent. Plant roots are like two-way streets. Water and nutrients are headed in, and organic acids, carbohydrates, and enzymes are leaking out. These outbound substances help acidify the soil zone directly surrounding the roots, dissolving nutrients, and providing sustenance for the microbial community which will continue to make even more nutrients available.

Years of farming practices can drastically alter the microbial health of your soil. Use a biological supplement with known beneficial organisms in it. Choose products that specify the organisms, population numbers, and proposed benefits.

The scientific literature is full of support for maintaining a thriving and diverse microbial community in the soil. Some benefits include disease suppression, increased mycorrhizal colonization and attachment to roots, and faster nutrient solubilization.

Let’s see how we’re doing… soil test – check, responsible fertilization – check, starter fertilizer – check, biological support – check. Looks good, but just like your crops roots, now is not the time to sit idly by and wait.

Monitor your crop and use plant and tissue sampling to see if things are headed in the right direction. When the reports come back from the lab, be prepared to take action. If there are nutrient deficiencies that will reduce yield or quality it is not too late. There are fast acting and highly available foliar nutrition products that can alleviate the deficiency.

Believe it or not, this practice of making foliar adjustments can make a big difference. In addition to supplying the plant with what it is lacking, foliar fertilization can increase the production of those desirable root exudates we discussed earlier. Choose foliar products with a small molecular weight carbon based carrier like the aromatic acids. Carbon is unique in its ability to bond with positively charged nutrient cations and negatively charged nutrient anions.

Anonymous quote from a crop adviser somewhere…

“All I ask is that you fertilize according to soil test recommendations, follow with starter fertilizers and biological support at planting, and make foliar adjustments according to tissue/plant samples."

These individual practices can seem too simple to make a difference, but when used as part of a combined program the results can be quite positive. These are some of the steps we use at Ag Tech Services, LLC to routinely boost spinach seed production here in the valley to quantities well above what the seed companies think a given variety can produce, and to push fresh market potato yields and quality to the next level.

Monday, October 24, 2011

Why spend money on soil samples?

Applying fertilizer to a crop without first pulling a soil sample is a tremendous waste of time and money. You are not saving money by not soil sampling. In fact you can be wasting a great deal of money if you use the wrong amount of the right fertilizer or any amount of the wrong fertilizer. Believe me, nobody can look at the soil surface and tell what your crop needs.

For those of you who do sample, I would remind you to pay for a full analysis, not a partial. Some people think that if they test for just pH, nitrogen, potassium, and phosphorus they will be covered. It is not that simple. More times than not a crop will respond to one of the minor nutrients more than the major ones. So don’t be cheap; buy the complete sample not a partial.

With the high cost of fertilizer it just makes good common sense to do a complete sample every year. If you don’t understand what all the numbers mean, contact a professional agronomist for help. The few dollars you may pay for help can easily save you thousands.

Monday, March 7, 2011

Maturing Potatoes in Western Washington

Why is it so hard to get skin set on a potato in Western Washington? This is a question that has confounded growers for years. So many times they just shrug it off by saying it’s the weather and you can’t change the weather. This is partially correct but let me explain the whole process and how you can change it.

Like all plants, potatoes are driven by five hormones. These are Indole-3-acetic acid (IAA), cytokinin (Cyt), gibberellic acid (GA), ethylene (ET), and absisic acid (ABA). The first three, IAA, Cyt, and GA are considered to be growth hormones while ET and ABA are considered to be stress and maturation hormones. The growth hormones are dominant at the stage of growth from seed germination, or sprout development, to seedling stage up to vegetative stage. All three of these hormones will be dominant at one time or another through bulking up to maturation. Prior to maturation, a hormone shift from IAA, Cyt, and GA over to ET and ABA must take place in order for the potato to be mature and the skins set at harvest.

That’s what needs to happen, but now let’s look at what does happen. In Western Washington, with our marine climate and high organic-matter soils, our potato plants are still dominated by GA when ABA dominance is needed. Nitrogen released from organic matter promotes the GA dominance so it must be blocked. This is where high rates of molybdenum come into play.

Molybdenum (Mo) works by blocking the impact of nitrate release and reducing GA dominance. When this occurs, ABA is the dominant hormone and maturation begins. Without this process, you will wait 40 to 50 days for skins to set leaving the tubers exposed to silver scurf infection. Dr. Phil Hamm from Oregon State University has said many times that to prevent silver scurf, growers need to get the tubers out of the ground as soon as possible.

To aid in the maturation process, two different directions can be taken. One direction is to apply a small amount of Stoller’s CoMo Classic (2% Cobalt, 3% Molybdenum) throughout the growing season. This will keep the plants from becoming overly dominant by GA later in the season. The second method is to apply Stoller’s Phos Moly (3-28-0-4%Mo) at a rate of one quart per acre three weeks before vine kill. At this rate of Mo, the hormone will force the ABA to increase which will reduce GA.

We cannot change the weather, climate, or organic matter but we can change how they impact the potato crop. No magic, just good science.

Thursday, February 10, 2011

The Science Behind What Grandma and Mom Were Doing.

Did you ever wonder what was happening as Mom was hacking and whacking at her petunias? Curious as to what was being achieved by Grandma lopping off new shoots from the apple tree? There are many things in life that we do to achieve a certain result without knowing the actual mechanisms in play.

Pruning and pinching are regular tasks in growing many flowers, ornamentals, vine crops, and trees. You could even look at mowing your grass as a form of pruning. More interestingly let’s look at what this does to the hormonal balance of the plant. There are five key hormones in plants, in two separate groups:
·                     Growth hormones – Cytokinins, Auxins, and Gibberellins.
·                     Stress hormones – Abscisic acid and Ethylene.

When we are pruning, pinching, and mowing we are influencing cytokinin and auxin ratios in the plant. Cytokinins are produced in the actively growing root tips and move upward in the plant stimulating processes such as shoot formation and branching. Auxins are primarily produced in the actively growing shoots and leaves. It is the ratio of these two hormones to each other and not the amount of either that matters. Both are required for cell division to take place. A higher amount of cytokinin coming from vigorous root growth will cause the plant to respond with vegetative growth to produce more auxin. When you prune or pinch a growing point and leaves off of a plant you are removing an auxin factory from production.

In the case of a rapidly growing vigorous plant with lots of auxin factories, pruning can be a good thing. Too much auxin production can overpower and inhibit cell division in the roots leading to a decline in root vigor, and hastening senescence and death. As auxin levels increase in the top of the plant and move downward it also causes dormancy in vegetative and reproductive buds. We would call this a top dominant situation, and when you cut off some of the auxin factories you are helping to return the plant to a more balanced root dominant situation.

In the case of a slower growing less vigorous plant, pruning can be a bad thing. Too little auxin production where very little auxin is available to make it down to the roots also limits root growth because cell division for new root growth will not be supported. Remember that root tips are only alive for a week or two, then they become a part of the “plumbing” and new root tips must be produced. 

When vegetative top growth outpaces your root growth (top dominance) you can have a beautiful plant with little endurance for production or stress. When there is a healthy, actively growing root mass under a plant during the entire season (root dominance), the plant can survive stress events and have good production. Four out of the five hormones controlling plant use of nutrition and governing how the plant grows are primarily made in the actively growing root tips.  Plant hormones must be available in sufficient quantities throughout the entire life cycle of the plant to maximize genetic expression and minimize stress.

By physically pruning/pinching shoots and branches Mom and Grandma were controlling the hormonal balance of the plant.  Most often they were putting the plant back into a balanced situation. Interestingly the same results can be achieved through nutrient support of hormone production, and sometimes by applying the hormones themselves.

Written by Brian Weems