Chapter 37 - Soil and Plant Nutrition

Macronutrient deficits

________ are the most common, with nitrogen, phosphorus, and potassium deficiencies being the most common.

ions

Positively charged ________ (cations) as potassium (K+), calcium (Ca2+), and magnesium (Mg2+) attach to negatively charged soil particles and are thus less easily lost by leaching.

rhizobacteria

Some ________ generate antibiotics, while others increase the availability of nutrients to plants.

agriculture

In ________, legume crops are cycled with other crops to replenish soil nitrogen.

Mycorrhizae

________ are mutualistic fungi- root connections.

Plant roots

________ take nutrients from the earth.

absorb water

Mycorrhizae's fungal hyphae ________ and minerals, which they then pass on to their plant hosts.

Topsoil

________ is a diverse environment teeming with bacteria, fungus, protists, animals, and plant roots.

atmospheric N2

Nitrogen- fixing bacteria convert ________ to nitrogenous minerals, which plants can use as a nitrogen source in organic synthesis.

Mechanical fracture

________ is caused by water freezing in rock fissures, and chemical fracturing is caused by weak acids in the soil.

Plant secretions

________ help the rhizosphere's energy demands.

Soil

________ is home to a live, diverse ecosystem.

Rhizobacteria

________ get their energy from the rhizosphere, a microorganism- rich ecosystem that is tightly linked to roots.

Plants

________ get the majority of their nitrogen via bacterial breakdown of humus and gaseous nitrogen- fixing.