GROWING MEDIA

Abstract

The invention relates to growing media, methods of manufacture thereof and their use in agriculture.

Claims

1. A growing medium comprising methylcellulose and kappa carrageenan, wherein the growing medium does not comprise soil, peat, coir, rock wool or an acrylate or acrylamide based hydrogel.

2. The growing medium as claimed in claim 1 comprising at least 50% w/w plant-derived hydrogel wherein the plant derived hydrogel comprises methylcellulose, kappa carrageenan and water.

3. The growing medium as claimed in claim 1, additionally comprising a gum.

4. The growing medium as claimed in claim 1, additionally comprising biochar.

5. The growing medium as claimed in claim 1, additionally comprising activated charcoal.

6. The growing medium as claimed in claim 1, additionally comprising lignin.

7. The growing medium as claimed in claim 1, additionally comprising locust bean gum.

8. The growing medium as claimed in claim 1, additionally comprising sodium bicarbonate.

9. The growing medium as claimed in claim 1, additionally comprising salicylic acid.

10. The growing medium as claimed in claim 1, additionally comprising xanthan gum.

11. The growing medium as claimed in claim 1, additionally comprising ammonium bicarbonate.

12. The growing medium as claimed in claim 1, additionally comprising potassium bitartrate.

13. The growing medium as claimed in claim 1, additionally comprising guar gum.

14. The use of a growing medium as claimed in claim 1 in agriculture.

15. The use of a growing medium as claimed in claim 1 in vertical farming.

16. The use of a growing medium as claimed in claim 1 in growing plants from seed.

17. A kit comprising: i) a growing medium as claimed in claim 1; and optionally ii) instructions for use.

18. A kit comprising: i) a growing medium as claimed in claim 1 in dehydrated form; and optionally ii) seeds; and optionally ii) instructions for use.

19. A process for preparing a growing medium as claimed in claim 1 which comprises mixing methyl cellulose and kappa carrageenan with water and allowing to set.

Description

BRIEF DESCRIPTION OF THE FIGURES

[1294] FIG. 1 shows the results from Experiment 7, copacabana lettuce growth. In each pair of photos, the first photo is Day 1 (post seed germination) and the second photo is the mature plants after they have grown under the experimental conditions for a further 28 days.

[1295] FIG. 2 shows the results from Experiment 7, sweet genovese basil growth. In each pair of photos, the first photo is Day 1 (post seed germination) and the second photo is the mature plants after they have grown under the experimental conditions for a further 34 days.

[1296] FIG. 3 shows the results from Experiment 7, helios spinach growth. In each pair of photos, the first photo is Day 1 (post seed germination) and the second photo is the mature plants after they have grown under the experimental conditions for a further 28 days.

[1297] FIG. 4 shows a table of the examples prepared by the procedure of Experiment 2.

EXAMPLES

Materials

[1298] The following compounds were used in the experiments: [1299] Sodium Alginate (NaAlg): high quality premium grade, halal, vegan; Sigma Aldrich [1300] Methyl cellulose (MC): food grade, vegan, non-GMO, gluten free, Intralabs [1301] Sodium carboxymethyl cellulose (NaCMC): High quality grade and food grade; Sigma Aldrich and Intralabs [1302] Biochar (BC): Industrial grade, Greenfield Eco solutions Ltd [1303] Xanthan Gum (XG): suitable for vegans, non-GMO, gluten free, Naturevibe Botanicals Store [1304] Pectin: highest quality food grade pectin powder, vegetarian, vegan and also halal/kosher friendly, Intra Labs [1305] Kappa Carrageenan (KC): Gelling Agent Vegan Vegetarian Alternative to Gelatine Halal Kosher Gluten Free, Mr.P Ingredients Store [1306] Glycerol: Sigma Aldrich [1307] Lignin: Sigma Aldrich [1308] Clay Particles (CP): Nanoclay, hydrophilic bentonite, Sigma Aldrich [1309] Activated Charcoal: HNCO Organics Private Limited [1310] Locus bean gum: Speciality Ingredients [1311] Sodium Bicarbonate: FunCakes [1312] Salicylic acid: Sigma Aldrich [1313] Guar gum: Speciality Ingredients [1314] Ammonium bicarbonate: FunCakes [1315] Cream of tartar: Speciality Ingredients

Experiment 1: Preparation of Hydrogel Compositions

General Preparation

[1316] The water in a beaker was put under a mixer and turned on. The components of the hydrogel in powder form were weighed and added to water under continuous stirring. The solution was mixed for 10 minutes at speed of 1500 RPM to obtain homogenous mixing.

Example 1

[1317] The components (methyl cellulose 3% w/v, xanthan gum 1% w/v, biochar 0.5% w/v) in powder form were weighed. Water at a temperature of 55 C. was added to a container and put under the mixer. The mixer (beater/whisker type) was turned ON and the weighed components were added to the hot water under continuous stirring. The solution was mixed for 10 minutes at speed of 1500 RPM for homogenous mixing and preparation of the gel.

[1318] The following hydrogels were prepared in a manner analogous to the above.

TABLE-US-00001 Example No Composition (% w/v) 2 3% MC 3 3% MC; 1% XG 4 3% MC; 0.5% BC 5 3% XG; 1% MC 6 3% XG 7 3% XG; 0.1% BC 8 2% XG; 1% NaAlg 9 4% NaAlg; 1% XG 10 3% MC; 1% NaAlg 11 3% MC; 2% NaAlg 12 3% MC; 3% NaAlg 13 3% MC; 4% NaAlg 14 3% XG; 1% NaAlg 15 3% XG; 2% NaAlg 16 3% XG; 3% NaAlg 17 3% XG; 4% NaAlg 18 3% MC; 2% XG 19 3% MC; 3% XG 20 3% MC; 4% XG 21 5% XG 22 3% MC; 0.25% KC 23 3% MC; 0.5% KC 24 1.5% KC 25 2% KC 26 3% KC 27 1% KC; 1% XG 28 1% KC; 2% XG 29 1% KC; 3% XG 30 2% CP; 3% XG 31 0.5% CP; 3% XG 32 1% CP; 3% XG 33 0.01% CP; 3% XG 34 0.02% CP; 3% XG 35 2.9% MC; 0.1% KC 36 2% KC; 1% MC 37 2% MC; 1% KC 38 1% MC; 1% XG; 1% KC 39 2% MC; 1% XG; 1% KC 40 2% MC; 1% XG; 0.5% KC 41 2% MC; 0.5% XG; 0.5% KC 42 2% MC; 0.5% XG; 1% KC 43 1% MC; 1% XG; 2% KC 44 0.5% MC; 1% XG; 2% KC 45 0.5% MC; 2% XG; 0.5% KC 46 0.5% MC; 2% XG; 1% KC 47 1.9% MC; 1.1% KC 48 1.8% MC; 1.2% KC 49 1.7% MC; 1.3% KC 50 1.6% MC; 1.4% KC 51 1.5% MC; 1.5% KC 52 1.4% MC; 1.6% KC 53 1.3% MC; 1.7% KC 54 1.3% MC; 1.8% KC 55 1.1% MC; 1.9% KC 56 1.5% MC; 1.5% KC; 0.5% BC 57 1.6% MC; 1.4% KC; 0.5% BC 58 2% MC; 1% KC; 0.5% BC 59 2% MC; 1% XG; 1% KC; 0.5% BC 60 3% MC; 4% XG; 0.5% BC 61 1% KC 62 1.1% KC 63 1.2% KC 64 1.3% KC 65 1.4% KC 66 1.5% MC; 1% KC; 0.5% BC 67 1.5% MC; 1.5% KC; 0.25% BC 68 1% MC; 1.5% KC; 0.5% BC 69 1.5% XG; 1.5% KC 70 0.1% KC; 0.5% Glycerol 71 1% KC; 2% MC; 0.5% Glycerol 72 0.8% KC; 2.2% MC; 0.5% Glycerol 73 3% NaCMC 74 1% KC; 2% NaCMC 75 2% NaCMC; 1% KC 76 2% KC; 1% NaCMC 77 3% NaCMC; 1% CP 78 3% NaCMC; 2% CP 79 3% NaCMC; 3% CP 80 1.1% NaCMC; 1.9% KC 81 1.2% NaCMC; 1.8% KC 82 1.3% NaCMC; 1.7% KC 83 1.4% NaCMC; 1.6% KC 84 1.5% NaCMC; 1.5% KC 85 1.6% NaCMC; 1.4% KC 86 1.7% NaCMC; 1.3% KC 87 1.6% NaCMC; 1.4% KC 88 1.8% NaCMC; 1.2% KC 89 1.9% NaCMC; 1% KC 90 1.9% NaCMC; 2% KC 91 1.9% NaCMC; 3% KC 92 1.9% NaCMC; 4% KC 93 1.9% NaCMC; 5% KC 94 1.9% NaCMC; 1% KC; % MC 95 1.9% NaCMC; 1% KC; 2% MC 96 1.9% NaCMC; 1% KC; 3% MC 97 1.9% NaCMC; 1% KC; 4% MC 98 1.9% NaCMC; 1% KC; 5% MC 99 1.8% NaCMC; 1% KC; 1% MC; 0.1 XG 100 1.8% NaCMC; 1% KC; 1% MC; 0.2% XG 101 1.4% KC; 0.1% MC 102 1.3% KC; 0.2% MC 103 1.2% KC; 0.3% MC 104 1.4% KC; 0.1% XG 105 1.3% KC; 0.2% XG 106 1.2% KC; 0.3% XG 107 2% MC; 1% Pectin 108 2% KC; 1% Pectin 109 2% MC; 1% KC; 0.5% Pectin 110 1% MC; 2% KC; 0.5% Pectin 111 1% MC; 1% KC; 1% Lignin; 0.5% Pectin 112 1% MC; 1% KC; 1% Pectin 113 1% MC; 1% Lignin; 1% Pectin 114 1% KC; 3% Lignin; 2% Pectin 115 3% MC; 3% Lignin; 2% Pectin 116 1.2% KC; 0.3% MC; 0.25% BC 117 1.5% KC; 1% BC; 1% MC 118 1% BC; 1% MC; 1.33% KC

Experiment 2: Alternative Preparation of Hydrogel Compositions

[1319] The components of the hydrogel in powder form were weighed and added to 200 ml boiling water under low speed continuous stirring. The speed of the mixer was then increased to high speed and after 3 mins of stirring 200 ml of 54 C. water was added. After 5 further minutes of mixing, 100 ml of boiling water was added and the mixture was stirred for a further 2 minutes to obtain a homogenous mixture.

[1320] A table of the examples prepared by this procedure is shown in FIG. 4. Where the total volume of water is 11 in FIG. 4, the water in the procedure above was doubled.

Experiment 3: Preparation of Shapes

[1321] The hydrogels described herein can be manufactured in different format, for example granules, sheets of different thicknesses, and blocks. They may be first left to set, and then dehydrated for ease of supply.

i) Sheets

[1322] To form sheets, gels prepared by the above procedure may be poured onto polystyrene trays and allowed to set. Sheets in dehydrated form may be prepared by placing the trays in a drying oven. A drying oven with a temperature controller may be used to provide uniform heat to the gels. Most gels uniformly dehydrate at 25-60 C. with good integrity and structure.

[1323] Alternatively, a vacuum oven drying (dehydrating) technique may be used to maintain a porous structure of the gels and prepare uniform sheets in dehydrated form. The vacuum helps to swell the gels and enhance the porosity within the sheet structure.

[1324] Other techniques that may be used to dehydrate gels in sheet form are freeze drying, microwave oven drying and air drying.

EXAMPLE

[1325] Example 58 was prepared by mixing the constituent ingredients for 10 minutes at a speed of 1200 RPM. The prepared gel was poured on to a polystyrene tray and then dehydrated in the drying oven at 45 C. for 24-36 hours.

[1326] The following sheets in dehydrated form were prepared by the above technique:

TABLE-US-00002 Sheet Number Hydrogel Weight before dehydration Weight after dehydration SH 36 Example 36 21 g 1 g SH 56 Example 56 18 g 1 g SH 58 Example 58 18 g 1 g SH 59 Example 59 20 g 1 g SH 67 Example 67 21 g 1 g SH 103 Example 103 19 g 1 g

ii) Cubes/Blocks

[1327] To form cubes or blocks, gels prepared by the above procedure may be poured into a hydrophobic mold and allowed to set for 15 minutes. After the solidification of the gels, they were cut into the shapes of cubes to form blocks.

EXAMPLE

[1328] Example 56 was prepared by the above procedure by mixing for 10 minutes at speed of 1200 RPM. The gel was poured on to a tray with hydrophobic surface (e.g. polystyrene) and left to set at 25 C. for 30 minutes. Once the gels were set, they were cut in shape of cubes to form blocks which were dehydrated in an oven at 45 C.

iii) Flakes

[1329] To form flakes, prepared gels may be air dehydrated and processed into flake form via a grinding machine.

iv) Granules Procedure

[1330] To form granules, prepared gels may be air dehydrated and crushed into granules via a grinding machine.

Experiment 4: Rewetability

[1331] Prior to use in agriculture, dehydrated gel-based products prepared as per the above need to be rewetted with water. Different sheets, for example, have different rewetting rates depending on their composition, and some crops may benefit from a longer sheet rewetting time. For example SH 36 can be rewetted and ready to sow seeds in 4 minutes and SH 56 can be rewetted for use in 8 minutes. However, it may be beneficial for some crops for SH 56, SH 58, SH 59, SH 67 and SH 103 to be rewetted for about 10 minutes. Of these gels, SH 103 and SH 36 can absorb the maximum quantity of water i.e., around 19 g/g (i.e. 19 g of water per 1 g of dehydrated gel).

TABLE-US-00003 Initial dehydrated Gel (sheet) weight (g) Soaking time Rewetted weight SH 36 1 g 4 mins 20 g SH 56 1 g 8 mins 13 g SH 58 1 g 8 mins 8 g SH 59 1 g 8 mins 7.9 g SH 67 1 g 8 mins 19 g SH 103 1 g 8 mins 12 g

Experiment 5: Germination

[1332] After rewetting the sheets, seeds were sown on them, and germination percentage was recorded after 5 days (room temperature, humidity 65%, dark).

TABLE-US-00004 Seed type Gel type (sheet) % Germination Spinach Freja SH 36 100 Spinach Freja SH 59 100 Spinach Freja SH 67 82 Spinach Helios SH 58 100 Basil SH 56 90 Basil SH 58 82 Lettuce SH 103 100

Experiment 6: Addition of Gels to Soil

[1333] Dehydrated sheets gels (10 g or 20 g or 30 g) were chopped and mixed with soil to make a total weight of 100 g of material per cell. A control (pure soil) was used to compare germination and growth rates of plants in pure soil and soil enhanced with gels. The growing media was put into a compartment tray for growing plants as multiples of three. Eight seeds were sown in each compartment and covered with foil to enhance humidity levels to facilitate seed germination.

[1334] After three days, the germination rate of the seeds was observed and counted to calculate germination percentage.

TABLE-US-00005 No. of Gel seeds Seeds % Medium Quantity (g) Seed Type sown Germinated Germination Yield (g) Soil 0 Lettuce Red 24 18 75 36.514 Green Salad Bowl Soil + SH 10 Lettuce Red 24 21 87.5 58.582 56 Green Salad Bowl Soil + SH 20 Lettuce Red 24 19 79.16 44.243 56 Green Salad Bowl Soil + SH 30 Lettuce Red 24 16 66.66 42.49 56 Green Salad Bowl

[1335] Overall, the growing soil medium enhanced with gels were found to have better yield than pure soil.

Experiment 7: Plant Growth

[1336] After seed germination in Experiment 6, the cells containing SH 56 (10% w/v) and soil (90% w/v), the lights were turned on in the chamber and temperature was set (23 C.light time for 16 hours) and 18 C. (dark time for 8 hours). The plants were irrigated with nutrient water as per requirement and left to mature for 4-5 weeks. The full-length plants were grown successfully as shown in FIG. 1 (lettuce), FIG. 2 (basil) and FIG. 3 (spinach).

Experiment 8: Degradation of Gel in Soil

[1337] In this experiment dehydrated flakes of Example 56 were added into soil (10 g dehydrated Example 56 and 90 g soil). Two types of soil were used-Loam (Supa Grow Blended Loam) and John Innes No 2.

[1338] All samples were measured for weight daily using a digital scale in the lab to measure weight. There other parameters including the conditions in the chambers i.e., 65% humidity/temperature/light levels were as follows. Lights were turned on in the chamber and temperature was set (23 C.light time for 16 hours) and 18 C. (dark time for 8 hours). Pot samples were given 10 ml of water on the Monday and Friday of each week

[1339] Overall all the samples decreased in weight, with a time until total disintegration of the gel in the soil of 17 weeks.

TABLE-US-00006 Weight Weight Weight Weight Weight Weight Weight Initial end end end end end end end weight Week 2 Week 5 Week 7 Week 9 Week 10 Week 17 week 18 (Day 1) Day 2 (g) (g) (g) (g) (g) (g) (g) 0.836 2.368 1.426 0.992 0.983 0.962 0.814 0.217 0.10

Statements

What is stated is: [1340] Statement 1. A growing medium comprising at least 50% w/w plant-derived hydrogel. [1341] Statement 2. A growing medium as stated in statement 1 comprising at least 80% w/w plant-derived hydrogel. [1342] Statement 3. A growing medium as stated in statement 1 or statement 2 wherein the plant-derived hydrogel comprises cellulose or a derivative thereof, starch, soy, plant protein, lignin, pectin, carrageenan, and/or gum. [1343] Statement 4. A growing medium as stated in any one of the preceding statements wherein the plant-derived hydrogel comprises methyl cellulose, xanthan gum, kappa carrageenan, sodium carboxymethyl cellulose and/or carboxymethyl cellulose. [1344] Statement 5. A growing medium as stated in any one of the previous statements, wherein the plant-derived hydrogel comprises methyl cellulose and kappa carrageenan. [1345] Statement 6. A growing medium as stated in any one of the previous statements, additionally comprising biochar, Psyllium, chitosan, barley seed powder, graphene, graphene oxide, reduced graphene oxide, agar, silk fibroin, genipin, honey, coconut oil, tea tree oil, charcoal, activated charcoal, vanillin, glycerol, clays, jute fibre and/or cotton. [1346] Statement 7. A growing medium as stated in any one of the previous statements, additionally comprising biochar. [1347] Statement 8. A growing medium comprising: [1348] 1-2.5% w/v methylcellulose; [1349] 0.5-2% w/v kappa carrageenan; and [1350] 0.25-0.75% w/v biochar; [1351] made to volume with water. [1352] Statement 9. A growing medium comprising: [1353] 0.1-0.5% w/v methylcellulose; and [1354] 1-1.5% w/v kappa carrageenan; [1355] made to volume with water. [1356] Statement 10. The use of a growing medium as stated in any one of statements 1-9 in agriculture. [1357] Statement 11. The use of a growing medium as stated in any one of statements 1-9 in vertical farming. [1358] Statement 12. The use of a growing medium as stated in any one of statements 1-9 in growing plants from seed. [1359] Statement 13. A kit comprising: [1360] i) a growing medium as stated in any one of statements 1-9; and optionally [1361] ii) instructions for use. [1362] Statement 14. A kit comprising: [1363] i) a growing medium as stated in any one of statements 1-9 in dehydrated form; and optionally [1364] ii) seeds; and optionally [1365] ii) instructions for use. [1366] Statement 15. A process for preparing a growing medium as stated in any one of statements 1-9, which comprises mixing: [1367] one or more plant-derived super absorbent polymers; [1368] and optionally additional ingredients selected from biochar, Psyllium, chitosan, barley seed powder, graphene, graphene oxide, reduced graphene oxide, agar, silk fibroin, genipin, honey, coconut oil, tea tree oil, charcoal, activated charcoal, vanillin, glycerol, clays, jute fibre and/or cotton [1369] with water and allowing to set.