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The LANG organic farm (Biolandbetrieb) in Germany, its ecological farming methods and their current potato year

With over 33 years of experience, the small-scale ecological farm LANG has made significant strides. Their traditional farming methods, including diverse crop rotation, animal husbandry, and potato cultivation, have been labor-intensive yet rewarding.

Serving approximately 300 customers through their farm store, they've not only provided organic produce but also increased soil humus levels and stored a substantial amount of CO² in the soil.

Since 2023, they've been implementing additional climate-adaptive measures such as altered crop rotations and regenerative soil management to leverage the increasingly extended vegetation periods during winter months. A notable addition to their practices is the Agroforestry system, referred to as their "future-proof field." Scientific support from the "Humus-Climate Network" has further strengthened their efforts.

Their collaboration with fellow farmers in a nationwide group enables diverse knowledge exchange on various measures. Their ongoing approach aims to enhance soil humus levels and resilience for a sustainable future.

The potato year so far at the LANG organic farm

Until 2022, potatoes at the LANG organic farm were planted in spring in often finely crumbled soil after a winter plough furrow and deep planting bed preparation - this has been tried and tested for many years. However, there should be a frost phase lasting several days in winter to crumble the ploughed soil (Loess soils with fluctuating clay content). This frost has now failed to appear as a result of climate change. Instead, winter cover crops grow throughout the winter and can produce good soil tilth in spring through intensive rooting. It is problematic to achieve the optimum soil condition in spring for ploughing (sometimes it is still too moist).

Article in the Starke Pferde Magazine featuring the Equi-Dyn

The Equi-Dyn shown above with a cutting roller at the front for shredding the plant residues, followed by a goosefoot sweep for cutting off the roots and then a crumbler roller, could do a comparable job in animal traction as the cutter on the tractor. Below you can see good soil tilth under the winter catch crop.

The first ploughing was carried out on 7 April 24 , the second cultivation with two passes up to approx. 10-12 cm was carried out on 12 and 13 April 24, always a little damp and with clod formation.

The potatoes were planted with a Hassia automatic planter mounted on a Fendt GT 250 (both approx. 50 years old and shown below). The potatoes are cared for with a KULT star hoe, also in the Fendt GT 250, equipped with hoeing shares and torsion tines if required, in order to be able to work over the entire surface. This device can also be operated in an animal traction system, installed in a horse-drawn GT that Thomas Lang developed earlier.

The potato planting took place on 13 April 2024. The soil condition was not optimal but sufficient. The old variety "Linda" is unfortunately no longer optimally adapted to climate change (temperatures up to 39°C and long periods of drought) and has a weak resistance to late blight. Therefore, a wider planting distance was chosen to achieve sufficient tuber size. The modern variety "Otolia" has more heat tolerance (again borderline), and late blight tolerance is better adapted. A narrow planting distance was chosen here to prevent oversizing.

Second hilling of the potatoes on 11 May 24 with torsion tines which do not work well in the cloddy soil.

Field development of potatoes: left "Ottolia" certified seed potatoes and right "Linda" reproduction.

Several hilling passes were carried out at the end of April to mid-May before and after field emergence to control weeds in the no-leaf stage and to crush the clods whenever a break in the rain allowed. The Otolia variety emerged quickly and evenly, the Linda only very slowly, hesitantly and weakly (my own relatively small planting material was stored cold until the planting date and may have been contaminated with viruses; this was an emergency solution as no organic Linda planting material was available this year).

On 28 May, Thomas Lang took advantage of a half-day break in the rain to hill up the crop at the final stage and because no cultivation seemed possible for the next 12 days due to the weather forecast or absence. He also sowed the undersow, actually a little too early (mixed Persian clover / Phacelia / a little camelina / Sudan grass approx. 20kg/ha) loosely in the bottom of the ridge with a very old Fendt GT seed box converted for this purpose.

The undersowing is intended to shade the ridges in autumn to ensure more biodiversity and soil improvement and to bind any excess nutrients in autumn. It was not possible to combine the planned simultaneous application of compost tea with a rear-mounted sprayer due to the short time available.

The concept of "mulch potato cultivation" with a layer of at least 5-7cm thick potato mulch applied shortly before emergence was abandoned this year because it was too costly and only really successful once in 4 trial years. There is also a risk of local over-fertilisation for several years and loss of nutrients.

It was still too early for the probably necessary potato beetle control with neem because beetles and egg clutches were present but no larvae could yet be found.

The first potato beetles were to be found on 21. May 24.

Last hilling and sowing of the undersow on 28 May.

The potato field on 30 May.

The first small larvae were found on June 10th and as there were numerous egg clutches, a significant increase in larval hatching was to be expected. Even if the official damage thresholds are still a long way off, in my experience this is the right time to treat the potatoes with Neem Azal T/S (2.5 litres/ha in 400 litres of water with double flat spray nozzles and approx. 2 bar pressure to wet the bushes as completely as possible). The product is effective for approx. 7 days, is relatively rainproof because it also penetrates the leaves, but an effect can only be seen after approx. 5-6 days while feeding stops earlier. Early treatment sometimes means that one measure is sufficient.

The larva in the last picture is actually already too big for meaningful control. New beetles were already visible again.

The undersown crop has germinated excellently due to the abundant rain and is almost too lush, whereas the potatoes could still do with a significant growth spurt, which is probably due to the slower mineralisation caused by the spring rotation of the catch crop. But the late blight pressure is significantly lower due to the sparse crop.

Treatment with copper to combat late blight is not planned.

A short summary of the Potato Year so far at LANG organic farm

Potato Varieties Used: Otolia predominantly firm-boiling; Linda – firm-boiling.

Source of Seed Potatoes: Otolia: Certified seed potatoes; Linda: Own seed potatoes, as no certified seed potatoes were available.

Previous Experience: Both varieties have been in cultivation for several years.

Advantages of Specific Varieties: Otolia: new variety, high heat and drought stress tolerance, good late blight (Phytophthora) resistance, good yield and flavour; Linda: old variety, little adapted to climate change but high consumer preference.

Field Plot Information: A flat field measuring approx. 0.25 hectares with rows running north-south.

Soil Type: Parabrown soil consisting of loess loam with a medium clay content.

Previous Use of the Plot: Winter wheat in 2023, a fast-growing summer catch crop and a winter catch crop (vetched rye and herbs)

Climate: Viticultural climate, i.e. today 11 (previously 10) degrees Celsius average annual temperature and today 600 (previously 700) mm annual precipitation; mild and precipitation-rich winters, little frost, almost continuous vegetation, pronounced pre-summer drought, often long periods of heat of 39-40 degrees Celsius.

Addiontal statements: Irrigation is neither possible nor economical.

Soil preparation: For the past three years, the crop rotation has been changed from

grain - summer catch crop - winter plough furrow - harrow deep 10-15 cm - potato planting to

grain - winter catch crop - in April shallow ploughing with cultivator - harrow deep - potato planting

with the aim of utilising the growth potential in winter, covering the soil and ensuring root growth and nutrient supply to the potatoes.

Power Source for Tillage Implements: The use of two cold-blooded horses as draught power was trialled for several years (also with a self-constructed GT horse) and had to be abandoned again due to the topography (slopes), farm structure (area units too large) and traffic situation (densely populated, no rounded-off location). Today, a 95 HP light four-wheel drive tractor is used for primary soil tillage, a Fendt GT with an associated potato planting machine, and a star hoe with ridges and torsion hoe for ridge maintenance.

Additional statements: It is important at LANG organic Farm that in the summer/autumn, the maturing potatoes in the ridge are protected from excessive heat by:

  • Mulch cover (at least 5 cm thick), which is very labor-intensive; requires 2-4 times the surface area, with a risk of over-fertilization;

  • Undersowing, which shades the ridges, but is not always successful.

Questions from the Lang organic farm: What methods can be used to grow potatoes successfully when temperatures rise (air up to 40 degrees Celsius and soil up to 40-50 degrees Celsius)?


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