Change of mineral element content in the common shrubs of Mediterranean zone. I. Macronutrients

Shrubs are characteristic of Mediterranean zone and are a significant feed source for goats. However, nutrient contents of shrubs vary significantly with climate, soil and especially with plant growth. There are a few studies on annual variations in mineral contents of shrubs in Marmara Region. Therefore, in this study, seasonal variation of macronutrients (N, P, K, Ca, Mg, S) of kermes oak (Quercus coccifera L.), mock privet (Phillyrea latifolia L.), prickly juniper (Juniperus oxycedrus L.), gall oak (Quercus infectoria Oliv.), Christ's-thorn (Paliurus spina-christi Miller), pink rockrose (Cistus creticus L.), thyme (Thymus longicaulis C. Presl.) and prickly burnet (Sarcopoterium spinosum (L.) Spach) were investigated for 14 months (October 2006 November 2007). Variation of macronutrients throughout the year was found to be significant for all shrubs. The concentrations of N, P, K, and S in the shrubs reached the highest levels during the April May months. However, Ca significantly decreased in April. Variation in Mg varied with shrub species. While the amount of N was able to meet the demands of goats during spring for all shrubs except for Paliurus spina-christi and Quercus infectoria, they were not able to meet the demands in other seasons. While Paliurus spina-christi had sufficient N every season, Quercus infectoria had also sufficient N during each season except for winter. P, K, and Ca were mostly observed at sufficient amounts for goats. While Juniperus oxycedrus had insufficient Mg in every season and mock privet in summer and autumn, Mg deficiency was not observed in other shrubs. Amounts of S were generally insufficient for the needs of goats.