Plants growing with hydrochar were vital plants wellnourished with N. Since their N content was independent of fertilizer
level, we used the 15N label to examine how much of the added KNO3 fertilizer was taken up by plants in the different
treatments. While plants growing on soil amended with pyrochar used large amounts (60e70%) of the added fertilizer N (Fig. 3),significantly lower amounts of fertilizer N were taken up by plants growing with corn silage as well as by plants growing with hydrochar; the latter using almost no fertilizer N (