Nutrient imbalance diagnosis in walnut orchards by using DRIS and PCA approaches in the northern part of erbil governorate-Iraq

الملخص EN

The use of Diagnosis and Recommendation Integrated System (DRIS) in studying the concept of a plant's nutritional balance has become an efficient method for assessing plant nutritional status; this method limits nutrient location depending on plant demand, enabling the nutritional balance between the nutrients in the leaf sample.

Aim of this study is to establish walnut DRIS norms and diagnosis nutrient imbalance by using DRIS and PCA (Principal component analysis) methods.

One hundred four leaf samples were collected during two consecutive years (2016 and 2017) from three walnut orchards in Erbil governorate/ Iraq.

The results showed that the smallest average NBI (Nutrient Balance Index) values are 125.6 and 27.2 respectively for both studied years which was coincided by high walnut productivity.

The most limiting nutrient descending order as Fe>Na>Ca>K>P>N>Mg respectively for first-year samples, and N>Na>P>Fe>Mg>Ca>K respectively for the second year.

From the result of PCA reveal that the nutrient concentration was explained in the low and high yield subgroups and the DRIS index by 61.95%, 87.75% and 58.67% respectively for first-year and 79.22%, 60% and 65.95% respectively for second-year sampling.

Several nutrient interventions in a single PC indicate that no nutrient imbalance in isolation could be diagnosed.