Update on our smallholder farmer trial

In a previous blog post, we introduced RegenZ’s Smallholder Farmer Trial in Sweetwaters, KZN. The purpose of the trial is to provide a community close to our hearts with nutrition inputs, application practices and planting guidelines and to test our Smallholder Farmer Starter Pack, which includes:

1. Maize and tuber potato seed
2. 2:3:4 (30) + Zinc Fertiliser
3. NanoCal
4. PopUp
5. AminoNPK
6. LAN Fertiliser

The objectives of the trials

• Potato trial: Identify which alternative treatment to standard fertilisers performed comparably to standard fertilisers.
• Maize trial: Identify which of the 9 maize cultivars showed superior growth in the location.

Fulfilling both these objectives will assist in making specialised recommendations to farmers based in KwaMnyandu, Pietermaritzburg.

How the trials worked

Both the maize and potato trial crops were planted on November 9, 2023, on land belonging to farmer Thulani Phakati.

• The maize seed was planted with a 35cm spacing.
• Potato seed (Valor variety) was planted with a 40cm spacing.
• The control is the smallholder farmers’ standard farming protocol, which includes goat manure
• In the plant furrow, we applied NanoCal at the equivalent of 10kg/ha and 2:3:4 at 500kg/ha for maize and 1,1 tons /ha for potatoes
• PopUp was applied via a knapsack sprayer in the furrow on top of the seed before it was closed.
• Both maize and potatoes were sprayed with AminoNPK at 1% concentration and 2% Real Cal 2 weeks after planting (an emergency program as a result of the hail). A weekly application of 1% AminoNPK was sprayed thereafter until a week before harvest. A knapsack sprayer was used to spray both the foliar and the soil.
• Two types of goat manure were applied at the same rate:
  • manure supplied by Thulani from goats on his premises
  • manure supplied by Justin Platt, which was collected about one year ago from Tugela Ferry
• LAN was applied as a side dress on February 27, 2024

The potato trial was harvested on March 13, 2024 (127 days, 18 weeks), and the maize trial was harvested on April 4, 2024 (148 days, 21 weeks).

Here’s a layout of how the trial was planted:

Potato trial results

Our hypothesis was that potatoes grown with standard, inorganic fertiliser would have the highest total weight, followed by those grown with 1kg standard fertiliser + 1.5kg goat manure treatment.

The results are shown in Figure 1: Potatoes with the highest total weight were those treated with standard fertiliser* application, followed by those treated with 3kg of Tugela Ferry manure and then those treated with half fertiliser and half Tugela Ferry manure. The control outperformed 3kg of Thulani’s goat manure. This is likely due to the differences in freshness, with Tugela Ferry manure being older than Thulani’s.

Table 1: Description of applied fertiliser treatment and the rate of application per 10m

Fertiliser Treatment

Fertiliser(kg)/10m

Description

Thulani’s goat manure

3

Manure supplied by Thulani from goats on his premises

TF goat manure

3

Manure collected about one year ago from Tugela Ferry

Fert +TF Goat manure

1+1.5

1kg Standard fertiliser + 1.5kg TF goat manure

Standard fertiliser

1

2:3:4( 30)

*Standard fertiliser refers to a fertiliser program for potato production recommended to farmers in KZN by Cedara Agricultural College: the application of 1100kg/ha 2:3:4 (30) at planting.

Recommendation

When Thulani cultivates potatoes, he typically relies solely on goat manure or sometimes applies no fertiliser at all. Based on this study, it is recommended that farmers in the area apply a mixture of 1kg fertiliser and 1.5kg goat manure to enhance their potato yield.

Maize trial results

At the time of measurement, most of the cobs were consumed by what is assumed to be birds or rats. The following parameters were observed for each maize variety:

Parameters DescriptionAverage number of cobs per plant Measurement of prolificacy per cultivar Milk line level Measurement of maturity per cultivar

• No cultivar showed any impressive prolificacy, as all cultivars only produced one fully developed cob per plant. Cap9646, Cap9006 Q and Cap341NG showed signs of potential secondary cob development, although this did not result in further dry matter production. This suggests that these cultivars may have a higher potential for prolificacy compared to others.  
• From observation, as per figure 2, Cap 341NG, Nelson’s Choice Certified synthetic open-pollinated variety (SOPV) and Nkunzi (all white maize) appear to produce cobs that are longer and larger than those of other varieties.
• Among the yellow maize, Cap9006Q is the longest, followed by Cap 9646 and Cap9503 being the shortest. Among the white maize, Isilo showed the shortest cob length  
• Regarding maturity, most of the varieties showed a 2/3 starch and 1/3 milk line, corresponding to approximately 35-38% dry matter. The only exceptions were Nelson’s Choice Certified as well as Okavango, both of which showed a ½ milkline and ½ starch, translating to about 30-35% dry matter. This implies that these varieties mature later than the rest of the varieties.
• Although quantitative data on plant height was not collected, an observation was made: Isilo, Cap9006Q, and Cap9503 appear to be shorter than the other cultivars.
• Farmer’s preference: Early yellow varieties are favoured, with less emphasis on cob length. Yellow maize is preferred for its perceived sweetness.

Recommendation

According to farmers’ preferences, it is advisable for them to consider cultivating Cap9006Q and Cap9646. These yellow varieties are characterised by their short stature and early ripening. making them favourable choices.

From a production standpoint, it is recommended that farmers opt for Cap341ng and Nkunzi for an early harvest, while Nelson Choice Certified is suggested for a late harvest.

Are you a smallholder farmer or do you have something to offer smallholder farmers? Please get in touch with the RegenZ team: https://regenz.co.za/small-holder-farmer/.