I. Allowing land to fallow II. Applying organic fertilizer III. Practicing monoculture IV. Growing legumes. Which of the following combinations will help to...

To improve soil fertility status, the combination of practices should aim at increasing soil nutrients and organic matter, reducing soil erosion, and promoting soil microorganisms. Out of the given options, applying organic fertilizer (II), growing legumes (IV), and allowing land to fallow (I) are practices that can improve soil fertility. Organic fertilizers increase soil organic matter content and nutrient availability, legumes improve soil nitrogen levels through nitrogen fixation, and allowing land to fallow promotes soil conservation by reducing soil erosion and increasing organic matter content. Practicing monoculture (III) can lead to soil depletion and reduction of soil nutrients over time. Therefore, the correct combination of practices that can help to improve soil fertility status is I, II, and IV only.