Planting a new parcel is a long term process and it seems crucial to study the physico-chemical characteristics of the parcel to choose the rootstock which suits best the soils and local climate conditions as well as yields objectives. This is also a great chance to think about planting, tillage practices and fertilizing strategies.

Observation and understanding of the parcel

On an existing vine parcel it seems important to observe the current vine to have a global understanding of the soil’s behavior in view of a future sampling. This will lead to:

• Determine vigorous zones, moist and dry zones
• Notice any deficiency in micro-nutrient elements,

These valuable elements will help you to choose areas to sample for further analysis.

If you wish to carry-on, you may dig a one meter deep trench which will give you valuable information on:

• The soil profile
• The structure and different horizons
• The root system behavior
• Subsoil compaction.

These datas will help you to find the best preparation methods to gain a better structured soil leading to plantation success.

Sampling

Sampling is carried-out under the row between 2 vines plants on a soil free of abnormal external moisture, not too dry, not too moist using a spade or an auger. This should be performed before any fertilizers input. If it is not the case sampling should be postponed for 6 months.

What depth ?

• 30 cm for the soil
• 60 cm for the subsoil

When the parcel is homogeneous

Determine 10 to 15 sampling spots thinking of the shape of a star. In order to obtain a better homogeneity the different samples are gathered together before sending them to the lab.

When the parcel is heterogeneous

 You follow the same sampling method as above for each previously observed zone. Make sure not to mix samples from different zones which may lead to incorrect test results and induce the wrong choice of rootstock

Elements to analyse

Particle size

 It gives information on the soil structural stability particularly on:

• The structure
• Looseness/compactness
• Permeability/Impermeability

It directly influences the exchange capacity between organic matter and chemical elements.

Organic matter

Crucial to obtain a good structure, it generates humus and has a great impact on soil aeration, drainage and nutrients uptake of the plant.

pH

It determines soil acidity bearing in mind that it might fluctuate by 1.5 in one year. According to the pH level the soil will need to be re-balanced or maintained with calcium carbonate input favouring calcareous sands. It is also strongly recommended to lime your soil before the Ca degradation to avoid hypoxia and acidifying process.

Lime

Chlorosis Risk Index or CRI takes into account the level of active calcium carbonate (Ca Co3) and extractable iron content Fe)². CRI is a key element in rootstock decision making.

Minerals

Quantify the level minerals in the soil such as nitrogen, calcium, phosphorus, potash and magnesium. The main goal is to detect potential uptake problems like excess in potash tends to reduce magnesium uptake or phosphorus zinc uptake.