(judgment as a matter of law granted to plaintiff on contract claim; defendant admitted contract with plaintiff for crop inputs and that no payment had been made; no evidence that warranty or representation regarding “target” yields to be met were made by plaintiff and defendant not entitled to withhold payment due to any misrepresentation; insufficient evidence presented that application of manganese by plaintiff did not result in manganese toxicity and cause reduced yields; evidence instead showed farm consistently underperformed, manganese toxicity in corn in state had never been documented, and only soil sample presented by defendant “had literally been baked” in defendant’s oven).