Leaf sampling and analysis
The reliability of analytical results and recommendations depends, ultimately on the sampling accuracy. The 3 stages in sampling are key, taking a representative sample, correct packing and immediate despatch to lab and supplying all the necessary background information.
A representative sampling path is required across the field. The W-pattern is adaptable to most shaped fields.
At each sampling site take several leaves at the same stage of development preferably the first fully expanded leaves working away from the growing point. Take leaves only not stems or roots. Avoid bruising or tearing the leaves, and do not include leaves showing pest, disease or other damage. Avoid dusty or soil contaminated plants. Mix the leaves thoroughly, and take sufficient to fill the jiffy bag. If the leaves are wet, blot them dry with clean absorbent material. The order form can then be placed in a plastic bag to keep it dry. Please don't forget to enclose it with the sample. Sample problem areas separately and try to take plants which are starting to exhibit symptoms rather than those that are very badly stunted or nearly dead.
LEAF SAMPLES FROM ORCHARDS
Select 20 trees or bushes of the same variety along the sampling path. Exclude pollinators and diseased or otherwise abnormal trees. Take 1 leaf per shoot from shoots on the north, south, east and west sides to give a total of 4 leaves per tree or bush. Young, fully expanded leaves should be chosen, from the current years extension growth. Mix the leaves thoroughly, and take sufficient to fill the sample bag. If the leaves are wet, blot them dry with clean, absorbent material. Label.
GRASSLAND HERBAGE SAMPLING
Select a sampling path as described previously. At each sampling site, use scissors or shears to cut the herbage 2.5-5 cm (1-2") above the ground. Only sample grass of the same height, and be careful to avoid contamination of the herbage with weeds, soil or animal droppings. Mix the herbage thoroughly, and take sufficient to fill a jiffy bag. If the herbage is wet, blot it dry with clean absorbent material. Label.
HAY, OTHER FODDER IN BULK, SILAGE
Hay can vary considerably within the bulk, therefore the following procedure is recommended. Avoiding outer bales, select 4-6 bales at random from the stack, open and take a sample from the centre of each. Mix thoroughly, and take sufficient to fill a jiffy bag. Label. Silage clamps are best sampled with a suitably designed corer, along a diagonal sampling path from front to back. If no corer is available, remove the top layer, and dig as deep as possible at each sampling point. Mix thoroughly, and take sufficient to fill a polythene bag. Seal securely. Label.