Crystallography in agriculture: green and red spinach (Amaranthus tricolor) grown on soil and hydroponic

Red spinach is said to content calcium oxalate based on chemical analysis. This study is an attempt to look at the calcium oxalate crystals in the leaves. Red spinach was planted on organic soil and hydroponic system using soluble inorganic nutrients. A hydroponic plant grows faster by almost two-fold compared to the on organic soil. Both methods produced the same reddish-purple stem and leaves on red Amaranth. The size of the stomata was also about the same (2.4 x 0.9 micron). However, scanning electron microscope images of the leaf showed the presence of much more and bigger calcium oxalate crystal in the hydroponic leaf than that of spinach planted on organic soil. Green spinach grew on organic soil also contained calcium crystal but with lesser amount compared with the red spinach. Energy Dispersive X-ray analysis indicates the presence of C, O, Ca, K, Mg, P, S, and Nb in the leaves. The result of this study is useful for farmers in making their selection of plants to grow and public health information as well.