The effect of mulched ridge and furrow micro catchment water harvesting on red pepper yield and quality features in Bafra Plain of Northern Turkey

For two decades, promising results have been obtained by ridge-furrow rainwater harvesting systems (RWHS) tofeed the increasing world population and cope with water scarcity and drought in semiarid and arid areas. A twoyearstudy in Turkey’s semi-humid Black Sea Region was conducted to examine RWHS’s effects on harvestedwater, soil water content, red pepper growth, yield, quality attributes, water consumption, and crop waterproductivity (WPc), crop water stress index (CWSI). The profitability of the system was examined by economicanalysis. For these purposes, three different polyethylene-covered ridge widths (RWHS1: 100 cm, RWHS2: 120cm, and RWHS3: 140 cm) were considered. To allow the harvested water infiltration root zone and grow redpepper, 80 cm width furrow areas with double plant rows were left between the covered ridges on contours. Tocompare the RWHS treatments, three conventional rainfed farming or dry farming treatments (DFS1, DFS2, andDFS3) with 90 cm, 100 cm, and 110 cm plant row distances were considered. Each treatment was replicated threetimes in the randomized block design experiment. Besides, a multiple regression model was developed to estimatethe runoff from the plastic-covered ridges by using independent parameters such as covered ridge ratios andrainfall amounts (R2 = 0.97). The red pepper consumed between 165 and 174 mm water in 2017 and 118–147mm in 2018. Maximum red pepper yields, which increased by 68% in 2017 and 149% in 2018, were derivedfrom RWHS1 as 33.2 and 27.19 t ha 1, respectively. As plastic-covered ridge width increased, red pepper yielddecreased because of lowering plant density. RWHS improved red pepper yield and significantly increased leafarea, plant height, fruit length, and diameter. RWHS produced Turkey’s highest red pepper WPc ratios, andRWHS1 improved WPc by 74% in 2017 and 169% in 2018. Although the red pepper consumed nearly the sameamount of water under whole treatments, CWSI was lower under RWHS treatments. It was determined thatsustainable red pepper farming according to the net income values under rainfed farmland in the region wouldnot be possible without using rainwater harvesting systems such as RWHS1.