Question

How is the the net production (NP) of a crop field calculated? What are factors that will affect the NP?

Answer 1

Answer:

In order to reach Net Primary Productivity, it is necessary to deduct from the Gross Primary Productivity the total organic matter that is consumed from a harvest field. So, we have to: Net Primary Productivity (NP) = Gross Primary Productivity - organic matter consumed in the respiration process of the plants.

Explanation:

The factors that influence the net and gross productivity of the ecosystem are: water, light, carbon dioxide and the available nutrients. The more sunlight the system receives, the greater the productivity. Thus, in tropical regions - where there is more sunlight and temperatures are higher throughout the year - productivity is higher than in places with a temperate, cold or polar climate.

It is estimated that 5% of sunlight is transformed into Gross Primary Productivity. The percentage transformed into Net Primary Productivity varies from 2.5% to 4%. For breathing, the plant takes advantage of 1% to 5% of solar energy. These data reveal that sunlight is not the only important factor for productivity: if there is no water in the place, as in deserts, productivity is low, as the soil does not offer conditions for the development of various species.

Answer 2

NPP can be directly assessed by measuring plant traits or harvesting plant material on the ground, but across large areas remotely sensed images can be used to estimate NPP.. im trying to help