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Native Corn Fed by Growth Stage: Up to Ten Ears on a Stalk

Kim Eun-ja, Natural Science Farming Institute, Konkuk University; Seoul Urban Agriculture Institute (title slide). Runs a natural farming test farm in Jeokseong, Paju. · South Korea

Spoken in Korean. Translated to English and checked line by line.

A farmer who runs a natural farming test farm in Paju fed Korean native corn by growth stage. She made her own Microbes-based fertilizers ("IMO5") for nitrogen, phosphorus and potassium and gave them at the times Master Cho teaches. Her seed came from a variety that, she was told, sets one ear per stalk, two at most. Her video shows a plant counted to ten ears, and she says most of the ten filled. This is a first-season farm report with no control, no yields and no dilutions.

What they found

The question

Can low-yielding Korean native corn set more ears if each nutrient is fed at the growth stage when the plant needs it, using homemade Microbes-based fertilizers (IMO5)?

How they tested it

Natural farming test farm of close to 1,000 pyeong (about 3,300 m²) in Jeokseong, Paju, 2016; about 25 crops grown, started in March. Korean native corn, seed from Seocheon, South Chungcheong; the seed's donor said it sets about one ear per stalk, two at most. She started late, so compost had already gone into the field before planting. Corn sown six or seven times, 10 days to two weeks apart. Not stated: plot size, plant numbers, spacing, any control or comparison, yields, ear weights, dilutions, or the amounts of each fertilizer (one dose is 'a handful per plant', and that word is itself uncertain). The only natural farming solution she names is her own IMO5; she mentions calcium phosphate liquid only as what most growers spray at the changeover.

What was compared
  • Slide plan (Fig. 2, 'Nutrient cycle') — Vegetative growth: N, K, P. Transition growth: P, K, N. Reproduction growth: Ca, K. Letter order and size suggest the main nutrient first. No solutions, rates or dilutions on the slide.
  • IMO5 fertilizers — Microbes (IMO) taken one step past IMO4: she made separate IMO5 batches for nitrogen, phosphorus and potassium, plus an NPK 'complex' mixed like a compound fertilizer. The phosphorus IMO5 was built on two materials the audio does not make clear (possibly rice bran and bone meal). Recipes and rates not given.
  • Before the changeover — Nitrogen, as the NPK 'complex' IMO5, in two small split doses.
  • Changeover, at about six leaves — The 'complex' with extra phosphorus added 1:1, made into IMO5 and given a handful(?) to each plant. She says Master Cho told her corn's changeover comes at about six leaves.
  • After ten or more true leaves — Feeding shifted to more nitrogen and potassium than phosphorus.
  • Tasseling — She says natural farming cuts nitrogen at this stage, and that she aimed for well-filled ears rather than big ones. She does not say exactly when she stopped the nitrogen.
Results
  1. One plant was counted to ten ears on video

    The video shows gloved hands going through a single stalk while voices count to nine, then ten. Her baseline is hearsay: the seed donor said this native corn sets one ear per stalk, two at most. No average across plants was given.

    ▶ 7:45 Said and shown on the slides

  2. Most of the ten ears filled; the lowest were a bit small

    She stresses that ten ears mean nothing if they are empty or tiny. With feeding 'at the right time, in the right amount', most of the ten bore grain. No weights or counts given.

    ▶ 9:06 As spoken

  3. Gap-toothed ears early on; fewer after balanced IMO5 feeding

    Fig. 4 (photo dated 2016-07-28): (B) malnutrition, fixed by balanced fertilization. She says the symptom 'largely went away'. Not counted.

    ▶ 16:15 Said and shown on the slides

  4. Staggered sowing cut poor-pollination ears

    Fig. 4 (A): bad pollination, fixed by pollinating steps. Corn sown six or seven times, 10 to 14 days apart, so pollen kept coming. Not counted.

    ▶ 16:44 Said and shown on the slides

  5. The native corn came out small but tasty

    Fig. 3, 'Korea native corn - small but tasty'. She says people who ate her produce were delighted and wanted to buy it; she blames tasteless Korean corn on nitrogen at tasseling.

    ▶ 15:41 Said and shown on the slides

  6. Large tomatoes failed from over-feeding; cherry tomatoes did well

    Pleased with the corn, she fed the big tomatoes too heavily. They did not turn out, so she pulled them midway and made them into liquid fertilizer.

    ▶ 17:50 As spoken

Hold it loosely
  • First season, one farm, started late in the year; she says herself it is not complete and she wanted to wait a year before presenting.
  • No control plot, no yields, no ear counts across the field, no weights. The 'ten ears' is one counted plant on video.
  • The baseline (one ear per stalk, two at most) is what the seed donor told her, not a measured comparison.
  • No recipes, dilutions or rates for any IMO5 batch; the phosphorus IMO5's ingredients were not heard clearly.
  • The field held compost before planting, so the result is not from IMO5 alone.
  • The schedule is described in speech only. The slide gives letters for each stage, not amounts, and its reproductive-stage calcium is never mentioned in speech.
For your farm
  • Feed by stage, not by calendar: nitrogen while the plant builds its body, phosphorus at the changeover, nitrogen cut back once the tassels come.
  • Corn keeps growing and setting ears at once, so its changeover is long; she watched leaf count (about six leaves, then ten true leaves) to time each shift.
  • Gap-toothed ears can come from two causes: poor feeding, or poor pollination. Sowing in batches every 10 to 14 days kept pollen coming.
  • Too much nitrogen to chase size can cost taste, and in her tomatoes it cost the crop.

Next to Master Cho's teaching

  • Agrees

    Nutrients by stage Cho's table: changeover needs much phosphorus, medium potassium and calcium, little nitrogen; vegetative needs much nitrogen; reproductive needs much calcium. Her slide's N-K-P, P-K-N, Ca-K plan follows the same order.

    Cho nutrient cycle prescription table (Oct 2017, transcribed) — 2. Changeover Period (교대기)

  • Agrees

    Cut nitrogen at reproductive growth Cho: in reproductive growth the plant stops spending carbohydrate on inorganic nitrogen and stores it in fruit. She cut nitrogen at tasseling for filled, tasty ears.

    Cho, Janong Natural Farming (2003), p. 81

  • Differs

    Corn's changeover at about six leaves She says Cho told her six leaves. In his 2017 seminar (machine-translated) Cho puts corn at type 2 with two leaves and changeover at four, one third of its 12–13 leaves.

    2017/Advanced Cho/advanced fruit/IMG_3202 @ 1:02:00 (translated)

  • Goes further

    IMO5 as fertilizer Cho lists IMO5 as IMO that decompose organic matter into fertilizer. She goes further and makes separate nitrogen, phosphorus and potassium IMO5s, timed to each stage.

    Cho, Janong Natural Farming (2003), p. 103

  • Unclear

    How many ears In 2017 Cho showed a photo of one corn plant with 13 ears from Konkuk's experimental farm near the 38th parallel, crediting calcium phosphate and water-soluble calcium. This talk shows and says up to ten. We cannot tell if his photo is her corn.

    2017/Advanced Cho/advanced fruit/IMG_3195 @ 0:40:12 (translated)

“Up to ten ears were set. But ten ears that are just empty husks mean nothing.”

▶ 8:41

“In natural farming we actually cut off nitrogen at that stage.”

▶ 15:17

“When we fed the right amount at the right time, the crops really answered with fruit.”

▶ 10:05

In this talk

  1. 0:00A test farm in Paju, 25 crops
  2. 1:50Why corn, why native seed
  3. 4:31Timing: the three growth stages
  4. 6:12Making IMO5 for N, P and K
  5. 6:50Video: counting the ears
  6. 9:27Taste, and beyond IMO4
  7. 10:34Corn's nutrient cycle
  8. 12:17The feeding schedule
  9. 14:53No nitrogen at tasseling
  10. 15:41Native corn and ear problems
  11. 16:44Staggered planting for pollination
  12. 17:47The tomatoes that failed
  13. 18:33Not finished yet
  14. 19:28A cancer patient's carrots
  15. 20:08Questions by email

Transcript

English translation, checked against the Korean as spoken. Click any time to play from there.