Soil ph is an important factor influencing the availability of micronutrients. as soil ph increases, the availability of manganese, zinc, and boron decreases. as shown in figure 1, manganese, zinc, and boron become more available as the ph drops. starter fertilizers u2026 Cal boron liquid. foliar open field fertigation. van iperen cal boron liquid is a pure and highly concentrated liquid calcium and boron fertilizer, formulated with liquid calcium nitrate. our product is a transparent, stable solution and is recommended as of early spring until fruit setting, especially as of bud development prior to flowering. Starter fertilizer rates and placement for corn. many producers in kansas could benefit by using starter fertilizer when planting corn. starter fertilizer is simply the placement of some fertilizer, usually nitrogen (n) and phosphorus (p), near the seed -- u2026 Peters professional liquid s.t.e.m. fertilizer is not organic certified. we do carry many organic fertilizers, as well as many fertilizers that are for specific kinds of blooms. we carry many products by the espoma company which are all organic fertilizers and plant foods.