The yield versus fertilizer input is shown in the graph. Consider the following statements based on this graph : I. Yield rate is zero at B and C. II. There is no yield with no fertilizer input. III. The yield is minimum at D. IV. The yield is neither minimum nor maximum at C. Which of the above statements are correct ?

The graph interpretation supports III and IV. Statement II is incorrect because standard yield–fertilizer response shows that with zero fertilizer the yield is at a minimum (not necessarily zero), so “no yield” is a mischaracterization [1]. Statement I is not supported: there is no evidence that yield is zero at points B and C, and agronomic texts indicate fertilizers raise yields rather than producing isolated zero-yield points at intermediate doses [2]. Statement III is consistent because point D corresponds to the minimum yield on the curve (the low/zero-fertilizer end) as described in yield–response analyses [1]. Statement IV is also true since C lies between extremes and is therefore neither the minimum nor the maximum on the typical response curve.

Sources

1. [1] https://www.researchgate.net/figure/Yield-Response-Vs-Fertilizer-application-curve-Explanation-to-the-plot-When-no_fig1_271156258
2. [2] Indian Economy, Vivek Singh (7th ed. 2023-24) > Chapter 9: Subsidies > 9.4 Fertilizer Subsidies > p. 287