Nutritional status of upland cotton by chemical analysis of soil and plant in a semi-arid environment

Upland cotton (Gossypium hirsutum L.) is one of the major agricultural export products of Turkey. This study was carried out in the area of Denizli, a semi-arid environment, which belongs to the Aegean region of Turkey, where cotton is a major crop. Soil and cotton leaf samples (Nazilli 84) were taken from 80 representative cotton fields (two samples from each sampling point) of a total area of 281.3 ha. In the soil samples pH, CaCO3, total soluble salt and some chemical analyses (N, P, K, Ca, Mg, Fe, Zn, Mn and Cu) were carried out. In the leaf samples macro and micro elements N, P, K, Ca, Mg, Fe, Zn, Mn and Cu were analyzed. The results of the soil and leaf analyses were compared in order to determine the nutritional status of the cotton soils and plants and thus to assess the potential of the cotton soils as accurately as possible, which in turn facilitates the possibility to work out specific and appropriate fertilization programs for the region. The soil analyses showed that the soils need 41.3% N, 100% P and 57.5% K fertilization. This result was confirmed by the plant analyses. Regarding micro-elements the soil analyses indicated only Zn deficiency (98.7%), but the leaf analyses also revealed Cu deficiency and showed only partly due to former Zn foliar sprayings Zn deficiency. As high pH and high lime concentrations of the soils can negatively affect the uptake of nutrients, this factor has to be taken into account when preparing fertilization programs and choosing the fertilizer form and type.