Effects of different fertilization practices on the N03-N, N, P, K, Ca, Mg, ash and dietary fibre contents of carrot

Abstract

The effects of different fertilization practices on the NO3-N, N, P, K, Ca, Mg, ash and dietary fibre contents of carrots were studied in field experiments in southern Finland. Unirrigated and irrigated placement and broadcast fertilization, NPK fertirrigations without basic fertilization, NPK fertirrigations with NPK basic fertilization and PK placement with N fertirrigations were compared. Further, single application was compared with split applications. The results of 1986 were analysed by contrast analysis. Fertilization practices affected the NO3-N content in carrot, and irrigation increased the NO3-N content. Highest NO3-N contents were observed with NPK fertirrigations treatments. Fertilization increased the N content of roots, and nitrogen content was higher with PK placement with N fertirrigations as compared to NPK fertirrigations without basic fertilization, or to NPK fertirrigations. Placement fertilization increased P content as compared to broadcast fertilization, NPK fertirrigations without basic fertilization, NPK fertirrigations or split application. Irrigation decreased P content. Fertilization increased the K contents of carrot roots as compared to unfertilized treatments, but there were no significant differences between fertilization practices. Fertilization had no effect on the Ca or Mg contents of carrot roots. Fertilization increased the ash content. Placement fertilization, single application and unirrigated single application yielded higher ash contents than did split application, NPK fertirrigations or PK placement with N fertirrigations. Fertilization and irrigation increased the dietary fibre content as compared to unfertilized and unirrigated treatments, respectively. Irrigated single application increased dietary fibre content as compared to split application and PK placement with N fertirrigations. Besides the fertilization experiment, samples from two organically cultivated fields were collected in order to obtain data concerning organically cultivated carrots.