Plants need nutrients primarily to support photosynthesis, and secondarily to support regeneragtion. Crop-captured nutrients are seldom lost during growth (except some potassium; K). Most nutrients move in large quantities from leaves to grains as the crop matures, especially P and N, so harvested materials can provide a reliable nutritional post-mortem on each crop. Nutrients for which grain analysis is useful are N, P, K, S, Mg, Mn, Zn & Cu. These show most redistribution, and critical concentrations are known for all of these grain nutrients. Grain nutrient concentrations multiplied by grain yield also accurately quantify nutrient removals from land, hence the need to replenish the soil. Grain analysis is new, so benchmarking helps users to assess their crop’s nutrient status. Benchmarking diagrams require results to be shared in big datasets, enabling comparisons with many similar crops from the same season, hence identifying nutritional successes and deficiencies. YEN Nutrition is an example of a Grain Nutrient Benchmarking service.