Effects of Water and Fertilizer Coupling on Growth Indexes of Watermelon under Mulched Drip Irrigation

Abstract

 The objective of this study was to investigate the effects of water and fertilizer coupling on the growth of watermelon under mulched drip irrigation. A field experiment was conducted to study the effects of different irrigation and fertilization levels on the yield and quality of watermelon by using a split block design. The growth indexes of watermelon such as maximum leaf width, stem diameter, root length and main vine length were systematically measured and analyzed. The results showed that the coupling effect of water and fertilizer had significant effects on the growth indexes of watermelon. Under suitable water and fertilizer supply conditions, the maximum leaf width, stem diameter, root length and main vine length of watermelon showed an increasing trend. Among,the combination of medium irrigation level (70-80% of field capacity) and medium fertilization level (80-90% of the recommended fertilization rate) had the best effect. All the growth indexes reached the maximum. Too high or too low levels of irrigation and fertilization will inhibit the growth of watermelon. The coupling effect of water and fertilizer was different in different growth stages, especially in the flowering and fruiting stage. In addition, the study also found that the effect of water and fertilizer coupling on root growth was particularly significant. Appropriate water and fertilizer supply can promote the development of root system to deep soil and improve the efficiency of water and fertilizer use.