Soil Fertility Study in the Douro Valley

The symptoms were exacerbated by the dry weather, making it an ideal year to observe the severity of the problem. Research suggests that acid toxicity, manganese deficiency, and boron deficiency are the most commonly identified causes. A study was conducted on 25 sick and healthy vines at the Quinta for careful examination. Soil and tissue samples were taken for analysis of suspected deficient elements. Soil compositions were analyzed for nutrient only, and Al-H acidity studies were conducted. Soil treatments will be applied daily, thoroughly under a planned protocol, this fall. Dolomitic limestone and other compounds have been arranged to apply the treatments better to grape health. Another area of study is the Coliar spray application of nutrients. Also, the São Lourenço vineyard near Sobroa will be studied with soil and foliar spray treatments. With the help of Professor Rhykerd, it was possible to study the mineral composition of the soil, row fertility, and the effects of potassium response on Port grapes. He explained why potassium response is so seldom obtained on sandy soils like many of theirs, even with low K soil tests. Soil testing has been hindered by the non-arrival of the new soil testing equipment from the Procnlfor project. However, a makeshift solution was chosen, and a new electronic soil test was obtained. This allows for direct readings in the field without making mathematical calculations. The standard curve was linear to over 200 ppm, so it is now possible to read pH and other parameters rapidly and without the need to dilute and re-run samples. The National Agricultural Library has a special program of literature searching for agricultural workers. The service provides access to a wide range of references, including articles on topics of interest to poor soils. The service also provides a comprehensive review of current research on topics such as nutrient deficiencies and their effects on plant growth. From Professor Janick, a review of a comprehensive report on "Hort Science" was received. Also, a donation of a set of the Journal of the Horticultural Society was made to our library.