Effects of different fertilization practices on the growth, yield and dry matter content of carrot

Abstract

The effects of different fertilization practices on the carrot root and shoot dry weights, yield, dry matter contents and root/shoot ratio were studied in field experiments. Unirrigated and irrigated placement and broadcast fertilization, fertirrigations without basic fertilization, fertirrigations with basic fertilization, and PK placement with N fertirrigations were compared. In addition, split application was compared to single application of nutrients. The soil nutrient levels were studied by soil analysis. The carrot root and shoot samples were collected three times during the growing period. Cv. Nantes Duke Notabene 370 was grown. The carrot shoots reached their maximum weight already by three months, whereas roots grew slowly during the first two months but grew considerably during both the third and fourth month. The root and shoot dry weights were positively correlated at all sampling dates in both years ( r ≥0.77***), The big photosynthetizing apparatus caused the production of high root yield. The placement fertilization of granular NPK fertilizer increased the yield as compared to broadcast of granular NPK fertilizer (p = 0.009**). The yield was also increased by the placement of P and K as compared to treatments without placement fertilization of P and K (p = 0.03*). There was no difference in yields between single application and split application. Irrigation decreased the yield in 1985 (p = 0.03*). In 1986the yield was significantly higher than in 1985 (p = 0.000***). At harvest the fertilization did not affect the dry matter content of carrot roots when compared with unfertilized treatments. The difference in dry matter content was greater between years (p = 0.000***) than between fertilization practices (p = 0.05*). The treatment PK placement with N fertirrigations yielded carrots with a higher dry matter content than did the NPK fertirrigations treatments. Besides the fertilization experiment samples from two organically cultivated fields were collected to obtain data concerning organically cultivated carrots and soils.