Utilization of Vinasse and Feldspar as Alternative Sources of Potassium Fertilizers and Their Effect on Some Soil Properties and Crop Yield in Sandy Soils

A field experiment was carried out for two successive seasons (winter season 2013/2014 and summer season 2014 ) on sandy soil at Ismailia Agric. Res. Station , Ismailia Governorate, Egypt (Latitude, 30^o 35' 41.901" N and longitude, 32^o 16' 45.834" E) to investigate the utilization of  vinasse and feldspar as alternative sources of potassium fertilizers on crop yield (pea and peanut), nutritional status and some soil properties. Two rates of vinasse V1 (75%) and V2 (100%) and two rates of feldspar mineral F1 (75%) and F2 (100%) from the recommended dose of potassium were used to complete the recommended dose of K fertilizers for pea and peanut crops, combination application of vinasse and feldspare were added as follow; (25 % V+ 75% F), (50% V + 50% F) and (75% V+ 25% F). Results show that available N, P and K in soil increased significantly by increasing the rate of applied vinasse and feldspar mineral. The superior treatment was (75% V + 25 %F), while, the pH values of soil and those of EC and OM % increased. The highest values of EC and OM % being recorded with vinasse (V2) and vinasse combined with feldspar (75% V+ 25% F). Total phenols values increased gradually by increasing the rate of vinasse, as compared to control treatment and decreased gradually with depth, the highest values of total phenols were recorded for the soil surface layer in presence of 100% vinasse alone followed by vinasse combined with feldspar. At the same time, the partially use of vinasse as a K fertilization in sandy soils is not causing any bioaccumulation of phenol compounds in sub soil layers. Results indicated that value of field capacity (FC), wilting point (WP) and available water (AW) increased by application of vinasse and feldspar mineral compared to control treatment at both studied seasons. Also data demonstrated that increasing rates of vinasse and feldspar mineral significantly increased (FC), (WP) and (AW) values. The high rate of vinasse (V2) and feldspar mineral (F2) being superior. Moreover, application of vinasse at rate 75% combined with feldspar at rate 25 % had recorded the highest values of soil moisture characteristics (FC, WP and AW). Moreover, application of vinasse at a rate of 75% combined with feldspar at a rate of 25 % had recorded the highest values of yield components as well as (N, P and K) total contents of grains and straw for both pea and peanut crops as compared to either control or other treatments. The application of vinasse combined with feldspar mineral (75% V+ 25%F) could be considered as a replacement for K- mineral fertilizers in sandy soils.