- Author: Mark Bolda
Below is a look at what happens to a soil following application of mustard seed meal (MSM) at 1.5 T per acre and mustard seed meal (again 1.5 T per acre) + crab meal (500# per acre) as separate treatments two weeks after fumigation with Ally 33 (67% AITC, 33% chloropicrin applied at 340# per acre on Oct 7).
Grower standard was methyl bromide/chloropicrin applied at 350# per acre. Planting took place Nov 3.
A soil sample taken on Nov 7 did not show differences in soil aspects analyzed between any of the treatments, although ammonium - N concentrations were surprisingly high (30 ppm and up) and nitrate - N numbers tended to be quite low (6 ppm and below).
Remarkably, look what has happened in the 4 weeks since that sample. Bear in mind that the grower has since sprinkled overhead several times and we had a good amount of rain as well. Commenting continues below the tables.
Unless otherwise indicated, units are in ppm of dry soil.
Table 1A. Soil analysis from December 7, 2016
Sample |
pH |
EC (dS/m) |
Nitrate – N |
Ammonium – N |
Methyl bromide grower standard |
7.4 |
0.9 |
11.3 |
4.7 |
Mustard Seed Meal |
7.1 |
1.7* |
34* |
20* |
Mustard Seed Meal + Crab Meal |
7* |
1.8* |
32* |
12* |
*Student's T-Test; different from grower standard at 5% level of significance.
Table 1B. Soil analysis from December 7, 2016
Sample |
(P) |
(K) |
(Ca) |
(SO4) |
(Mg) |
(Mn) |
Fe |
Na in meq/L |
Cl in meq/L |
Methyl bromide grower standard |
51 |
148 |
3100 |
278 |
178 |
8.9 |
18 |
1.9 |
3.2 |
Mustard Seed Meal |
54 |
190* |
2933 |
318 |
193 |
19.2* |
16 |
1.5 |
1.9 |
Mustard Seed Meal + Crab Meal |
60 |
185* |
3100 |
589 |
150 |
20.1* |
16 |
1.5 |
1.9 |
*Student's T-Test, different from grower standard at 5% level of significance.
One sees immediately that the pH has fallen, even significantly, in plots treated with mustard seed meal and mustard seed meal + crab meal. This is not surprising, since in the month's time since the initial sample on Nov 7, the ammonium has clearly nitrified (releasing 2 H+ ions per molecule, in turn acidifying the soil) creating a big pool of nitrates which have gone up significantly over the grower standard.
EC has gone up a bit due to the higher nitrates (NOT because of sodium or chloride), and interestingly levels of manganese (Mn) a mineral sensitive to acidification apparently, have soared in both MSM treated plots. Levels of available potassium (K) have gone up significantly also in MSM treated plots.
Quite interesting on the whole. By the way, a soil report like this makes for pretty good reading, and outside of the EC which is for the time being a little high in the MSM plots, all the other numbers are right where I like to see them.
Stay tuned on this one; we are following all of this trial through the season.
- Author: Mark Bolda
Since digging for strawberry plants destined for Salinas and Watsonville started at Macdoel just a few days ago, I thought it would be judicious to have a look at how many chill hours we've accumulated so far and what it means for additions to supplemental chill, especially for our day neutral varieties.
I checked with the Lassen Canyon nursery chill accumulator here: http://lassencanyonnursery.com/cumulative-chilling-hours-and-weather-conditions/ .
Looking at the data for Oct 18 of this year and running my calculations via the Utah model (which subtracts chill hours for temperatures realized above 60oF, see previous posts), we have currently accumulated 325 units of chill. Given that last year's chill accumulation was 164 units and by most commentator's opinion a decent accumulation, 325 accumulated chill units this year is very satisfactory.
So what does this mean for adjustments on supplemental chill? Personally, I think growers may want to take the strong field chill in stride, and now look forward to what sort of winter we are going to have. Looking at the NOAA data, we are probably in for a weak “La Niña” system this year, which according to the “Color Outlook Maps” for temperature, we have something like a 40% chance of having slightly warmer than normal temperatures in November, December and January.
The question then is what sort of adjustment should or needs to be made to supplemental chill. It's actually not an easy question to answer, given the strong field chill. Then again the odds of a slightly warmer than normal winter would give me some reason to err on the side of caution and go a tad longer than customary on the supplemental chill .
/span>- Author: Mark Bolda
Article out of this morning's Wall Street Journal. Apparently American consumers are going wild over knobbled carrots, weird apples and mis-shapen potatoes.
Consumers, we have a deal for you! Catfaced strawberry fruit and poorly pollinated blackberries we can deliver by the pallet. Step right up!
Seriously, this is something pretty intriguing.
- Author: Mark Bolda
- Author: Tim Hartz
The question has come up more than a few times from industry participants on how to adjust nitrogen (N) inputs for strawberry varieties more productive and of larger plant size than Albion for which the original DRIS study was done.
Simple math says one could just increase simply N uptake estimate to cover the added fruit and bigger plant, so if Monterey produces 20% more fruit, and is that much larger a plant, one just adds 20% more nitrogen to the standard annual fertility program to make up the difference. However, as simple as this math may seem, it could quite possibly be incorrect, since it is not at all unknown that different strawberry varieties have variations in N content in the fruit and leaves.
The work to determine N content of Monterey compared to that of Albion was done over two samplings (one in early May, the other mid-July) of five fields of Albion and five fields of Monterey. We found that Monterey had marginally higher N concentrations in both the leaves (Table 1) and the fruit (Table 2) on both sample dates. An evaluation of plant size, without fruit, found that Monterey also ran about 20% larger than Albion from the five fields sampled.
From this information, we can say that N uptake is at least as high in Monterey as in Albion per unit of plant growth. That is to say, if a grower expects and has experienced 20-25% increases in fruit yield with Monterey over that of Albion, then the amount of N uptake to support that level of productivity will also be 20-25% higher than for Albion.
We need to be careful here however. This is not a call for growers of Monterey to automatically increase their N fertilizer additions by 25%. If a grower is finding his or her seasonal practices in the lower half of typical grower practice, then an increase in nitrogen application could be tested, but if a grower is already using a lot of N, say above 250 lbs per acre, then that might be enough to absorb the higher N requirement of Monterey.
Table 1: Nitrogen (N) concentrations in dry leaves
Variety |
4-5 May |
12-15 July |
Monterey |
3.02 % |
2.71 % |
Albion |
2.81 % |
2.44 % |
Table 2: Nitrogen (N) concentrations in dried fruit
Variety |
4-5 May |
12-15 July |
Monterey |
1.28 % |
1.06 % |
Albion |
1.22 % |
0.93 % |
Many thanks to the growers who participated in this study, and generously allowed me to tear plants out of their fields for the plant size sampling.
- Author: Mark Bolda
Really well written article here by local journalist Lily Stoicheff on what has happened to our local Ollalieberries.
Those of you who have been around this area for a while recall that Ollalieberries used to be a staple here in the South County and now they are all but gone. My take on the situation shows up about mid-way in the article; I'm flattered to be included in such a good piece of writing together with well known local growers Vince and Noah Gizdich and ocean scientist Gary Griggs.
http://goodtimes.sc/cover-stories/whats-happening-santa-cruzs-olallieberries/