Optimizing Lime Application and Symbiotic Nitrogen Fixation in Soybean Cultivation

Play an AI-generated podcast conversation about this lesson

What is the main source of nitrogen for a soybean crop at a 65 bu/ac yield level in Nebraska?

Symbiotic fixation of nitrogen from the atmosphere

Nodules formation on soybean roots

Residual nitrogen in the soil and nitrogen from mineralized organic matter (correct)

Nitrogen fertilizer application

What is the expected outcome of applying micronutrients like boron, copper, and molybdenum to soybeans grown in Nebraska?

Significant increase in yield

Increased disease resistance

Decrease in yield

No significant yield increase (correct)

Which factor makes it less likely for elevated postharvest soil nitrate levels to result in significant nitrate leaching below the root zone?

Deficiencies of micronutrients like manganese

Symbiotic fixation of nitrogen from the atmosphere (correct)

Application of nitrogen fertilizer

Presence of white mold

What is the consequence of applying manure for narrow-row soybeans based on research findings in other states?

Increase in white mold Signup and view all the answers

Why are deficiencies of boron, chlorine, copper, manganese, and molybdenum not observed in soybeans grown in Nebraska?

Sufficient levels of these micronutrients in Nebraska soils Signup and view all the answers

What is the preferred practice for short- and long-term benefits to improve soybean yield?

Seed inoculation with Bradyrhizobium japonicum bacteria Signup and view all the answers

In which type of soil conditions is soybean yield more likely to benefit from nitrogen fertilizer application?

Soil with less than 1.5 percent organic matter Signup and view all the answers

What can be inferred if active nodules (dark pink center) are absent from soybean roots?

There is a deficiency of Bradyrhizobium japonicum bacteria Signup and view all the answers

When should nitrogen fertilizer be ideally applied to soybean fields?

As late as early pod fill Signup and view all the answers

Why is routine nitrogen application not recommended for soybean crops?

It leads to lodging-induced yield reduction Signup and view all the answers

Where does soybean obtain 25 to 75 percent of its plant nitrogen from?

Soil Signup and view all the answers

When do nodules start to appear on soybean roots?

After the first trifoliolate leaf emerges Signup and view all the answers

In which scenario is seed inoculation recommended for soybean production?

When Bradyrhizobium japonicum bacteria presence is doubtful Signup and view all the answers

What percentage of nitrogen needed by soybean can be supplied by symbiotic fixation with Bradyrhizobium japonicum bacteria?

Approximately 75% Signup and view all the answers

Under what conditions may the supply of nitrogen from soil and nodules be inadequate for soybean?

Low pH Signup and view all the answers

What is the main reason for iron chlorosis in plants according to the text?

Inability of the plant to effectively use iron Signup and view all the answers

How can high levels of nitrate-nitrogen in the soil affect iron availability to soybean plants?

Decrease iron availability Signup and view all the answers

What is a recommended management practice to address iron chlorosis in soybean plants?

Consulting with a seed dealer for tolerant varieties Signup and view all the answers

In which scenario is it unlikely that tolerant soybean varieties will produce well?

When there was severe iron chlorosis in corn or grain sorghum Signup and view all the answers

How does low soybean plant density affect the severity of iron chlorosis?

It makes iron chlorosis more severe Signup and view all the answers

What is a method producers can use to control fertilizer application based on management zone maps?

Manual application using a global positioning system (GPS) Signup and view all the answers

In which field conditions is zinc fertilization likely to be beneficial?

Fields low in organic matter and eroded Signup and view all the answers

What happens if soybean does not show zinc deficiency after a previous corn crop?

Soybean will not exhibit deficiency symptoms due to the previous corn crop Signup and view all the answers

How can manure application before planting soybean affect yield?

Increase yield by about 3 bu/ac in the first year Signup and view all the answers

To avoid surpassing the soybean nitrogen removal rate, how should manure rates be calculated?

To not surpass half of the soybean nitrogen removal rate Signup and view all the answers