Buying a Farm – a Valuer’s perspective | Growing a valuable pecan nut orchard part 2

PECAN NUTS AND SOIL

Pecan nut trees do well in a well-drained deep soil with a medium texture. The alluvial soils along rivers are excellent for pecan nut trees, provided the permanent water level is at least 5 m or more below the soil surface to ensure good drainage.

Clay content preferably not more than 35%, but is best above 10%. Very clayey or sandy soils have limitations in respect of water supply. No restricting layers should be present in the top 3 m of soil.

Suitable soil types

• Clovelly, Griffen and Inanda forms – Soil depth can be restricting and clay content must be between 10% and 35%.
• Hutton form – Good soil depth, but clay content must be between 10 and 35%.
• Oakleaf form – Appears along rivers and streams, very deep and fertile.

Marginally suitable soil types (special management practices required)

• Avalon, Longlands and Bainsvlei forms – A limiting layer appears from a depth of 60 cm to 1 m downwards. Not an ideal soil, especially in wet seasons and irrigation must be managed carefully.
• Glenrosa form – Soil is always shallow and limiting. Less water per irrigation must be applied, but more often. Trees tend to be smaller due to limiting root depth.
• Shortlands – Swelling and shrinking occur with wetting and desiccation. Carefully controlled irrigation is required.

Unsuitable soil types

• Bonheim, Arcadia, Swartland and Valsrivier forms – Strong structural development and clayey content, which both inhibit root penetration.
• Cartref and Fernwood forms – Very low water-holding capacity.
• Estcourt, Kroonstad, Wasbank and Pinedene forms – Restrictive layers are common.

WATER REQUIREMENTS OF PECANS

Establishing permanent crops are expensive and without irrigation water all that money

is lost, especially in the areas such as the Northern Cape and Vaalharts where the rainfall is too low for dryland production of pecans. The table and graph below shows the rainfall versus the water requirements of pecans per month. The shortfall needs to be supplied by means of irrigation.

Pecan nut trees are deciduous and should not to be irrigated during May to September, when it should be in rest. The young trees, however, should be watered from August onwards to ensure proper development, as can be seen in the table and graph below.

When most orchards are still young and do not need that much water, farmers tend to argue that they do not even use all the allocated water. The problem, however, surfaces when the orchards are mature and need their full volume of water. Orchards are then irrigated below the optimum level and produce accordingly. The valuer therefore has to make sure that, even if all the orchards are young, only the correct number of hectares are valued as irrigated and the balance at a lower value as dryland crops.

*This article was originally published on the Farmer’s Weekly website

** Extract of a presentation prepared by Lyndon Storer, Nedbank Ltd Regional Valuer, used with permission**