Concentrations of nitrogen, phosphorus, sulphur, magnesium, and calcium in North Island pastures in relation to plant and animal nutrition

An extensive survey involving 5862 geographical sites was carried out to obtain information on the concentrations of nitrogen, phosphorus, sulphur, magnesium, and calcium in grass‐clover pastures of the North Island of New Zealand. Results indicate that N was the major limiting factor for active plant growth with over 70% of the sites being found to be deficient. The associated P and S concentrations were high and few of the sites were found to be deficient. P deficiencies were most common in pastures from the important sheep farming areas. There was no indication from the survey that Mg or Ca was limiting plant growth. In relation to animal nutrition all but a few sites (1%) would have satisfied the nutritional requirements of lambs whereas over 20% of the sites had insufficient P and Mg to satisfy the dietary requirements of lactating dairy cows.