Biological fixation of nitrogen has made a great contribution to Brazilian agriculture, and the country is a leader in research in these areas. On ...

Biological fixation of nitrogen has made a great contribution to Brazilian agriculture, and the country is a leader in research in these areas. On this topic, it is correct to affirm:

1. Soybean yield is increased by applying a dose of 50-70 kg of nitrogen in coverage, in order to cover the plant's needs in the grain filling phase.
2. Nitrogen fixation in soybeans is increased by fertilization with cobalt and molybdenum, the main limiting factors for fixation in this crop.
3. In winter pastures, the grains are inoculated with specific strains through pelleting, using rock phosphate to cover the seeds, due to the low pH of the soils used.
4. Integrated corn production discourages the use of leguminous cover crops due to the large amounts of nitrogen supplied, which benefit invaders and cause nutritional imbalances.
5. Inoculants containing bacteria of the genera Azospirillum and Herbaspirillum, capable of increasing the yield of grasses, are available on the market.
a. Only 2 and 4 are true
b. Only 1 and 3 are true
c. Only 1, 3 and 5 are true
d. Only 2, 3 and 4 are true
e. Only 4 and 5 are true