Index
- Nutrients demand/uptake/removal
- Generic fertilizers recommendations
- General fertilizing principles for cucumbers
- Pre-plant fertilizers for growth in soil beds
- During crop growth
- Drip irrigation
- No phosphatic fertilizer
The recommendations appearing in this document should be regarded as a general guide only. The exact fertilization program should be determined according to the specific crop needs, soil and water conditions, and the grower’s experience. For detailed recommendations, consult a local Haifa representative.
Disclaimer: Any use of the information given here is made at the reader’s sole risk. Haifa Chemicals Ltd. provides no warranty whatsoever for "Error Free" data, nor does it warrants the results that may be obtained from use of the provided data, or as to the accuracy, reliability or content of any information provided here.
In no event will Haifa Chemicals Ltd. or its employees be liable for any damage or punitive damages arising out of the use of or inability to use the data included.
4.1 Nutrients demand/uptake/removal
One ton of cucumber fruits removes from the soil:
|
|
N |
P2O5 |
K2O |
|
Grams |
800 – 1,350 |
270 - 900 |
1,350 – 2,250 |
|
Lbs |
1.8 - 3 |
0.6 - 2.0 l |
3 – 5 |
Table 4.1: Recommended plant nutrients under different growing conditions and expected yields
|
Growing method |
Expected yield (t/ha) |
N |
P2O5 |
K2O |
MgO |
CaO |
|
Kg / ha |
||||||
|
Under glass |
300 |
450-500 |
200-250 |
800-1,000 |
130 |
300 |
|
Outdoor crop |
High-yielding |
170 |
130 |
270 |
|
|
|
Outdoor crop |
30-40 |
100 |
100 |
200 |
|
|
|
Outdoor crop |
30 |
50 |
40 |
80 |
|
|
|
Outdoor crop |
15 |
47 |
13 |
65 |
|
|
4.2 Generic fertilizers recommendations
Table 4.2: A general fool-proof recommendation for N-P-K fertilization regime and timing allocation before and during the growth season, based on soil tests.
|
Fertilizer timing |
Nitrogen |
Soil phosphorus level (kg/ha P2O5) |
Soil potassium level (kg/ha K2O) |
||||||
|
Low |
Med |
High |
Very high |
Low |
Med |
High |
Very high |
||
|
Total recommended |
120-140 |
170 |
120 |
60 |
30 |
230 |
170 |
120 |
60 |
|
Pre-plant: broadcast & incorporate |
60 |
120 |
60 |
0 |
0 |
170 |
120 |
60 |
0 |
|
Band-place* |
30 |
60 |
60 |
60 |
30 |
60 |
60 |
60 |
60 |
|
Side-dress when vines begin to run, or fertigate |
30 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
*15 cm to side of seed row and 10 cm deep
4.2.1 General fertilizing principles for cucumbers
Pre-plant treatments
Amending soil pH
Cucumbers prefer light textured soils that are well drained, high in organic matter and have a pH of 6 - 6.8. Adapted to a wide-range of soils, but will produce early in sandy soils. Cucumbers are fairly tolerant to acid soils (down to pH 5.5).
Greenhouse cucumbers generally grow quite well in a wide range of soil pH (5.5-7.5), but a pH of 6.0-6.5 for mineral soils and a pH of 5.0-5.5 for organic soils are generally accepted as optimum.
When the pH is too low, add ground calcitic limestone, or an equal amount of dolomitic limestone when the magnesium level in the soil is low, to raise it to a desirable level. Use the rates given in Table 4.3 as a guide; the actual lime requirement is best assessed by an appropriate laboratory test.
Table 4.3: Lime requirements for correcting soil pH to 6.5
|
Soil pH |
Sandy Loam |
Loam, silty loam |
Clay loam, organic |
|
Lime mass (t/ha) |
|||
|
6.0 |
3.0 |
4.5 |
6.0 |
|
5.5 |
6.0 |
9.0 |
12.0 |
|
5.0 |
9.0 |
12.0 |
18.0 |
|
4.5 |
12.0 |
15.0 |
24.0 |
|
4.0 |
15.0 |
18.0 |
30.0 |
Note: The rates of lime suggested are for the top 15 cm of soil. If acidity has to be corrected to a greater soil depth, increase the rates accordingly.
Usually the pH in most greenhouse mineral soils is above the optimum pH range (6.0-6.5). A simple, though temporary, solution to a high pH problem is to add peat, without neutralizing its acidity with limestone. Peat also helps to maintain a good soil structure, but it must be added yearly to make up for loss through decomposition.
Pre-plant fertilizers for growth in soil beds
Apply pre-plant fertilizers after soil steaming and leaching, and incorporate them into the greenhouse soil. Add these fertilizers to the limestone that may be needed for adjusting the pH level of the soil (Table 4.3). Add as much of the required calcium and phosphorus as possible as a base dressing, because these nutrients store effectively in the soil and their absence from liquid feeds prevents most clogging problems of the irrigation system. Provide the calcium in the form of limestone and the phosphorus in the form of superphosphate, both finely ground.
Furthermore, these nutrients, by nature of their source and their ability to bind to soil particles, are released slowly into the soil solution and therefore do not raise the total amount of salts dramatically, nor do they upset the nutrient balance of the soils to which they are added as a base dressing. Also, supply a good portion of potassium along with magnesium, as base fertilizer; the ratio of potassium to magnesium in the soil should be 2:1. Avoid applying nitrogen.
Make the final decision on base fertilization after receiving the soil test results and consulting with your horticultural crop adviser. Treat the recommended rates of base fertilizers (Table 4.4) as a general guide only.
Table 4.4: Recommendations for base fertilizer
|
Fertilizer |
Amount |
|
|
kg/ha |
lbs/ac |
|
|
Superphosphate (0-20-0, fine grade) |
250 |
225 |
|
Potassium sulfate |
500 |
445 |
|
Magnesium sulfate |
250 |
225 |
|
Add the following in combination, if needed: |
||
|
Calcitic limestone |
800 |
715 |
|
Peat |
800 bales/ha |
|
|
Incorporate the relevant fertilizers into the soil to avoid micronutrient deficiencies, indicated by soil analysis |
||
During crop growth, the most important element needed is nitrogen. It should be supplied in the irrigation water (fertigation) at each irrigation, from soluble fertilizer materials, such as potassium nitrate (13-0-46), e.g. Multi-K™; calcium nitrate (15.5-0-0+26.5 CaO), e.g. Haifa Cal™; or ammonium nitrate (33-0-0). During the first few weeks after transplanting, fertigate with 6-11 kg/ha (5-10 lbs/ac) of N per week, during fruit production.
In soilless systems, plants are grown with a complete nutrient solution, composed of potassium nitrate (13-0-46), e.g. Multi-K™+ mono-ammonium phosphate (12-61-0) e.g. Haifa MAP™or monopotassium phosphate, e.g. Haifa MKP™+ calcium nitrate (15.5-0-0+26.5 CaO), e.g. Haifa Cal™, magnesium nitrate (11-0-0+16MgO), e.g. Magnisal™, or with a complete N-P-K controlled-release fertilizer (CRF), e.g. Multicote™, at rates of 0.6-1.2 kg/m3 (1-2 lb/yd3) of nitrogen, or with a combination of the soluble- and the CRF materials. When used in combination, rates for each material should be reduced by 30-40%. Nutrient solution should be applied every irrigation by fertigation. Frequency of application will depend upon plant size and greenhouse temperature, but will vary from once or twice daily, immediately after transplanting, to several times per day on warm days during harvest.
Always apply some pre-plant N-P-K to assure good development of the seedlings and first vegetative stage of the plants.
Adjust rates to soil type, and soil test results.
|
|
Kg / ha |
Lbs / acre |
|
Nitrogen |
50-70 |
45-63 |
|
Phosphorus (P2O5) |
10-120 |
9-108 |
|
Potassium (K2O) |
10-170 |
9-153 |
See Table 4.2 for more specific rates, based on soil tests.
If drip irrigation is used, apply the 60 kg/ha (55 lbs/acre) N preplant.
Then, during growth season apply 0.6-1.1 kg/ha (0.5 to 1 lbs/acre) N daily, or 3.5-7 kg/ha (3-6 lbs./acre) N on a weekly basis, through the drip system.
If plastic mulching is practiced, the N rate can be reduced because N losses from leaching are greatly reduced. For this culture system, it is recommended to apply 60 kg/ha (50 lbs/acre) N broadcast preplant over the row, just prior to laying the plastic.
At vining, when the plant roots have reached the edge of the plastic, side-dress 35 kg/ha (30 lbs/acre) N on either side of the plastic.
Soil pH: Optimum soil pH range is 5.8-7.0. If the soil pH is below 5.8 and the available soil calcium is less than 2,200 kg/ha (2,000 lbs/acre), apply 2,200 kg/ha (2,000 lbs/acre) of agricultural lime 8 to 12 weeks before planting.
Lime and dolomitic limestone: If soil test indicates less than 70 ppm magnesium, pre-plant application of Magnesite or Dolomite is recommended, at rates indicated in paragraph 2.5, or to apply magnesium sulfate (9.8% Mg), or its equivalent at 170-220 kg/ha (150 - 200 lbs/acre), by preplant broadcasting and incorporating.
Lime and phosphates: If both lime and phosphates are required, both should be incorporated together 8 - 12 weeks before planting.
Phosphate: On soils very low in available phosphate, apply 1,700 kg/ha (1,500 lbs/acre) of triple super-phosphate (0-47-0) or its equivalent. If grower chooses to apply the phosphorus just before planting, mono-ammonium phosphate fertilizer grade (11-52-0) at 1,700 kg/ha (1,500 lbs/acre) should be incorporated in the planting row 25-30 cm (10 - 12 inches) deep.
Organic manures are useful even for outdoor crops, especially in low CEC soils.
Side dressing treatments
The N application should be split into as many applications as possible. If fertigation
(Nutrigation™) equipment is available N should be applied in every irrigation pulse. Otherwise, fortnightly dressings should be done along the harvesting period.
Side-dressing N: It is recommended to apply 50 kg/ha (45 lb. per acre) N in a band to either side of the row when plants are rapidly vining. At least half of the nitrogen should be in the nitrate (NO3) form.
For fresh market cucumbers, an additional 35 kg/ha (30 lbs/acre) N is usually added when the plants have 2-4 leaves and vines are just starting to fall over into the rows, but no more than 45 kg/ha (40 lbs./ac) of N or K2O should be applied at any one time. Pickling cucumbers are not responding to any additional N applications due to their short harvest period.
Additional application(s) should be made every two weeks with the onset of harvest as side dress and covered with surface soil. The following options are recommended:
- A 3:1 mixture of ammonium sulfate (21-0-0): Multi-K™(13-0-46), at the rate of 220 kg/ha (200 lbs/ acre)
- A 1:1 mixture of urea (46-0-0): Multi-K™(13-0-46), at the rate of 220 kg/ha (200 lbs/ acre)
- An N-P-K complex water soluble fertilizers, such as Poly-Feed™at the equivalent N:K ratios may be fertigated = Nutrigated™ (injected through the irrigation system).
Deficiencies of Mg and of B, Fe and Mn, may occur and demand direct application of these nutrients, by the methods and rates mentioned in Chapter 2, paragraphs: 2.5, 2.7-2.9.
Table 4.5: Recommendations for the application rates and weeks allocation of soluble fertilizers to be evenly broadcasted on the soil in a soil cucumber greenhouse, irrigated by flooding, as determined for greenhouses in Canada. Source: Papadopoulos.
Do not apply this program as is, to a drip-irrigated plot as it will produce very high salt concentrations near the root system.
|
Week from planting |
Potassium nitrate |
Calcium nitrate |
Amm. nitrate |
10-52-10 |
20-5-30 |
Magnesium sulfate |
|
Kg/ha |
||||||
|
1 |
|
|
|
150 |
|
|
|
2 |
50 |
50 |
|
|
100 |
100 |
|
3 |
50 |
|
|
|
100 |
|
|
4 |
50 |
100 |
|
|
100 |
100 |
|
5 |
50 |
|
|
|
100 |
|
|
6 |
100 |
100 |
|
|
100 |
100 |
|
7 |
100 |
|
|
|
100 |
|
|
8 |
100 |
100 |
50 |
|
100 |
|
|
9 |
100 |
|
|
|
100 |
100 |
|
10 |
100 |
100 |
50 |
|
100 |
|
|
11 |
100 |
|
|
|
100 |
|
|
12 |
100 |
100 |
50 |
|
100 |
100 |
|
13 |
100 |
|
|
|
100 |
|
|
14 |
100 |
100 |
50 |
|
100 |
|
|
15 |
100 |
|
|
|
100 |
100 |
|
16 |
100 |
100 |
50 |
|
100 |
|
|
17 |
100 |
|
|
|
100 |
|
|
18 |
100 |
100 |
50 |
|
100 |
100 |
|
19 |
100 |
|
|
|
100 |
|
|
20 |
100 |
100 |
50 |
|
100 |
|
|
21 |
100 |
|
|
|
100 |
|
|
22 |
|
|
|
|
100 |
|
|
23 |
|
|
|
|
100 |
|
*Caution: If fertilizers are first mixed in concentrated stock solutions before they are applied to the crop, group them as indicated by the colors grouping. Do not mix in the same concentrated solution a fertilizer containing calcium and one containing sulfate or phosphate, because such a mixture forms a thick suspension that can plug watering equipment.
Note: Choose soluble fertilizer formulations that are as free as possible of chlorides, sulfates, and carbonates.
Table 4.6: Recommendations for the application rates and allocation by weeks of generic soluble fertilizers in a soil cucumber greenhouse, fertigated by drip irrigation. As determined for greenhouses in Canada, source: Papadopoulos.
|
Week from planting |
Fertilizers in stock solution A* (kg/1,000 L) |
Fertilizers in stock solution B* (kg/1,000 L) |
Irrigation |
|||||||
|
CN |
PN |
Amm. nitrate |
MKP |
MgSO4 |
MgN |
Volume (L/plant/day) |
EC (mS/cm) |
|||
|
|
Spring Crop |
|||||||||
|
1 |
50 |
0 |
0 |
100 |
25 |
|
0.4 |
1.94 |
||
|
2 |
50 |
35 |
0 |
15 |
25 |
|
0.6 |
2.09 |
||
|
3 |
35 |
50 |
10 |
15 |
25 |
|
0.8 |
2.24 |
||
|
4 |
35 |
50 |
15 |
15 |
25 |
|
1.0 |
2.46 |
||
|
5 |
35 |
55 |
15 |
15 |
25 |
|
1.2 |
2.54 |
||
|
6 |
35 |
60 |
15 |
15 |
25 |
|
1.6 |
2.61 |
||
|
7 |
35 |
65 |
15 |
15 |
25 |
|
2.0 |
2.69 |
||
|
8 |
35 |
70 |
15 |
15 |
25 |
|
2.2 |
2.69 |
||
|
9 |
35 |
70 |
15 |
15 |
25 |
|
2.4 |
2.69 |
||
|
10 |
35 |
70 |
15 |
15 |
25 |
|
2.6 |
2.69 |
||
|
11 |
35 |
70 |
15 |
15 |
25 |
|
2.8 |
2.69 |
||
|
12-17 |
35 |
60 |
15 |
15 |
|
35 |
4.0 |
2.46 |
||
|
18-22 |
35 |
55 |
15 |
15 |
|
35 |
5.0 |
2.46 |
||
|
23- end |
35 |
50 |
15 |
15 |
|
35 |
4.0 |
2.31 |
||
|
|
Fall crop |
|||||||||
|
1 |
50 |
|
|
100 |
25 |
|
0.4 |
1.94 |
||
|
2 |
50 |
35 |
|
15 |
25 |
|
0.8 |
2.09 |
||
|
3 |
35 |
50 |
10 |
15 |
25 |
|
1.0 |
2.24 |
||
|
4 |
35 |
50 |
15 |
15 |
25 |
|
1.2 |
2.46 |
||
|
5-12 |
35 |
50 |
15 |
15 |
|
35 |
3.0 |
2.46 |
||
|
13- end |
35 |
50 |
15 |
15 |
|
35 |
2.0 |
2.31 |
||
CN = Calcium nitrate (15.5-0-0-26CaO) e.g. Haifa Cal
PN = Potassium nitrate (13-0-46), e.g. Multi-K™
Amm. nitrate = Ammonium nitrate (33.5-0-0)
MKP = mono-potassium phosphate (0-52-34), e.g. Haifa MKP™
MgN = magnesium nitrate (11-0-0+16MgO), e.g. Magnisal™
*Caution: If fertilizers are first mixed in thick stock solutions before they are applied to the crop, group them as indicated. Do not mix in the same concentrated solution a fertilizer containing calcium and one containing sulfate or phosphate, as such a mixture results in a thick suspension that can plug watering equipment.
Notes:
- Trace elements must also be added to all the above fertilizer feeds; a typical trace element mix (e.g., Haifa Micro™ Combchelated micronutrient mix) contains 7.1% Fe, 3.48% Mn, 1.02% Zn, 0.76% Cu, All as EDTA chelates. 0.485% Mo as ammonium molybdate; when added to the stock solution at the rate of 1 kg/1000 L it contributes to the final solution 0.7 ppm Fe, 0.2 ppm Mn, 0.04 ppm Zn, 0.01 ppm Cu, 0.13 ppm B, & 0.006 ppm Mo, with a 1:100 dilution ratio.
- Dissolve the given amount of each fertilizer, including trace elements, in 1000 L of water and add to the irrigation water in equal doses, ideally with a multihead fertilizer injector. Start injection at a very low rate and increase the rate of injection progressively, and uniformly on all heads, until the desired EC is achieved. Adjust the pH of the fertigation solution to 5.5 by injecting a dilute solution of phosphoric, nitric, or sulfuric acid. Alternatively, dissolve the prescribed fertilizers, including the micronutrient mix, into 100 000 L of water, adjust the pH, and apply directly to the crop.
- The recommended strength of the stock solutions is within the working range of a fertilizer injector with a 1:100 mixing ratio. If a fertilizer injector with a 1:200 mixing ratio is used, double the amount of each fertilizer. Make similar adjustments for fertilizer injectors with other mixing ratios. If the solubility limit of a fertilizer (e.g., potassium nitrate) is exceeded, prepare more than one stock solution of the same fertilizer and divide the amount of the fertilizer equally between the stocks.
Table 4.7: Nutrient concentration in the final nutrient solution when one part of each of stock solutions A and B, prepared as prescribed in Table 4.6, are mixed with 98 parts of water (i.e. 1:100 dilution ratio). Source: Papadopoulos.
|
Week |
N-NO3 |
N-NH4 |
P |
K |
Ca |
Mg |
Fe |
Mn |
Zn |
Cu |
B |
MO |
Expected EC * (mS/cm) |
|
|
Spring Crop |
||||||||||||
|
1 |
72 |
3 |
235 |
300 |
95 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
1.94 |
|
2 |
117 |
15 |
35 |
175 |
95 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.09 |
|
3 |
140 |
25 |
35 |
133 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.24 |
|
4 |
145 |
25 |
35 |
133 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.46 |
|
5 |
151 |
25 |
35 |
251 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.54 |
|
6 |
158 |
25 |
35 |
270 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.61 |
|
7 |
164 |
25 |
35 |
289 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.69 |
|
8-11 |
170 |
25 |
35 |
308 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.76 |
|
12-17 |
196 |
25 |
35 |
270 |
67 |
32 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.46 |
|
18-22 |
189 |
25 |
35 |
251 |
67 |
32 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.39 |
|
23- end |
183 |
25 |
35 |
233 |
67 |
32 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.31 |
|
|
Fall crop |
||||||||||||
|
1 |
72 |
3 |
235 |
300 |
95 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
1.94 |
|
2 |
122 |
12 |
35 |
175 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.09 |
|
3 |
140 |
15 |
35 |
133 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.24 |
|
4 |
145 |
25 |
35 |
133 |
67 |
25 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.46 |
|
5-12 |
186 |
25 |
35 |
270 |
67 |
32 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.46 |
|
13- end |
189 |
25 |
35 |
251 |
67 |
32 |
0.7 |
0.2 |
0.04 |
0.01 |
0.13 |
0.006 |
2.39 |
*The EC of the water has been assumed at 0.045 S/cm and is included.
Table 4.8: Recommended nutrient levels for cucumbers in NFT solution in normal water.
Note: The NFT system is not recommended for long-term cucumber crops because of frequent, and unresolved, crop losses from widespread root death.
|
Stock solution A (1,000 Liter tank) |
Stock solution B (1,000 Liter tank) |
||
|
Fertilizer |
mass |
Fertilizer |
mass |
|
Calcium nitrate |
44.4 kg |
Mono potassium phosphate (MKP) |
22.0 kg |
|
Potassium nitrate |
62.7 kg |
Magnesium sulfate |
50.0 kg |
|
Ammonium nitrate |
5.0 kg |
Iron chelate (13% Fe)* |
1.0 kg |
|
|
|
Manganese sulfate (25% Mn)* |
250 g |
|
|
|
Boric acid (14% B)* |
90 g |
|
|
|
Copper sulfate (25% Cu)* |
30 g |
|
|
|
Zinc sulfate (23% zinc)* |
35 g |
|
|
|
Ammonium molybdate (57% Mo)* |
8 g |
* Alternatively, include 2.0 kg of Haifa Micro™ Soilless combinationchelated micronutrient mix; which provides the following micronutrient concentrations: 1.4 ppm Fe, 0.4 ppm Mn, 0.08 ppm Zn, 0.26 ppm B, 0.02 ppm Cu, and 0.012 ppm Mo.
Notes:
- Prepare the final solution by adding equal volumes of both stock solutions in water until a recommended final solution EC of 3.28 mS/cm is achieved; adjust the pH to 6.2 by adding phosphoric (low-light conditions) or nitric (high-light conditions) acid. Ideally, stock solutions are mixed and pH is adjusted automatically by electrical conductivity and pH controllers.
- When starting a new crop, begin with an EC of 2.24 mS/cm and gradually increase to 3.28 mS/cm over 1 week.
- A background EC of 0.045-0.091 mS/cm from the water supply is assumed.
Assuming a dilution ratio of 1:100 for stock solutions A and B, the theoretical nutrient concentrations in the circulating diluted NFT solution are as follows:
|
Nutrient |
ppm |
|
Nitrate (NO3-N) |
156 |
|
Ammonium (NH4-N) |
12 |
|
Phosphorus |
50 |
|
Potassium |
302 |
|
Calcium |
84 |
|
Magnesium |
50 |
|
Iron |
1.3 |
|
Manganese |
0.62 |
|
Boron |
0.12 |
|
Copper |
0.07 |
|
Zinc |
0.08 |
|
Molybdenum |
0.03 |
Table 4.9: Recommended nutrient levels for cucumbers in NFT solution in hardwater.
|
Stock solution A (1,000 Liter tank) |
Stock solution B (1,000 Liter tank) |
Stock solution C (1,000 Liter tank) |
|||
|
Fertilizer |
mass |
Fertilizer |
mass |
Fertilizer |
Volume |
|
Calcium nitrate |
50.0 kg |
Potassium nitrate |
80.0 kg |
Nitric acid (67%) |
54 L |
|
|
|
Potassium sulfate |
40.0 kg |
Phosphoric acid (85%) |
24 L |
|
|
|
Magnesium sulfate |
60.0 kg |
|
|
|
|
|
Ammonium nitrate |
0.6 kg |
|
|
|
|
|
Iron chelate (13% Fe) |
3.0 kg |
|
|
|
|
|
Manganese sulfate (25% Mn) |
400 g |
|
|
|
|
|
Boric acid (14% B) |
240g |
|
|
|
|
|
Copper sulfate (25% Cu) |
80 g |
|
|
|
|
|
Zinc sulfate (23% zinc) |
40 g |
|
|
|
|
|
Ammonium molybdate (57% Mo) |
10 g |
|
|
No phosphatic fertilizer has been included other than the phosphoric acid in stock solution C.
Where the water is not particularly hard and the acid requirement is correspondingly low, include 1.5 kg of mono-potassium phosphate, e.g. Haifa MKP, in stock solution B, while decreasing the amount of potassium sulfate from 40 to 30 kg.
Note: Assuming a dilution ratio of 1:100 for stock solutions A and B, the theoretical nutrient concentrations in the circulating diluted NFT solution are as follows:
|
Nutrient |
ppm |
Remarks |
|
Nitrate (NO3-N) |
192 |
The nitric acid of stock solution C supplies additional nitrogen |
|
Ammonium (NH4-N) |
12 |
|
|
Phosphorus |
0 |
The phosphoric acid of stock solution C supplies the phosphorus |
|
Potassium |
490 |
|
|
Calcium |
85 |
The calcium content of the water supply has not been taken into account. |
|
Magnesium |
59 |
|
|
Iron |
4.5 |
|
|
Manganese |
1.0 |
|
|
Boron |
0.34 |
|
|
Copper |
0.2 |
|
|
Zinc |
0.09 |
|
|
Molybdenum |
0.05 |
|
Need more information about growing cucumbers? You can always return to the cucumber fertilizer & cucumber crop gui de table of contents or the cucumber growth stages
