Pulses introduction

Question 1

1. what are the three factors that determines the performance/productivity/yield of legumes or grains?

Answer 1

The three important factors that effects the performance of the crops are

1. genetic (Genotype) of the plant
2. management( intercultural operations, pest and disease,)
3. Environment( climatic and soil conditions)

Yield = Genetic x Management x Environment

Question 2

1. elaborate on Production Ecological Principle

Answer 2

It explains the production situations(actual, water and nutrient limited and potential) where there is a yield gap between those situations. In each specified situation the gaps are caused by limited by factors(actual- reducing factors are weeds, pests, disease and pollutants, where as in water nutrient limited case the limiting factors are water and nutrient. in both of this situation due to these limiting factors the plants cannot fluorish fully and the production level is also less. but in the potential situations where the limiting factors are taken care there is defining factors such as Co2, Radiation, Temperature, crop features which determine the potential of the crop at its highest productivity.

Question 3

1. What is the main significance of legumes or the pulses?

Answer 3

Food security (source of plant-based protein, vitamins and
minerals
• Human health (prevent and manage, obesity, diabetes,
etc.)
• Sustainable agriculture (biologically fix nitrogen)
The great diversity of species allows a large adaptation
to environmental conditions and to cropping systems
alfalfa, beans, lentils, peas, faba beans, chick pea, lupin, Vetch.

Question 4

1. What are some of the agronomic benefits of pulses/legumes?

Answer 4

The great diversity of species allows a large adaptation
to environmental conditions and to cropping systems.

Decrease of greenhouse gases (N2O et CO2
) compared to fertilized crops, at field scale
and at crop sequence scale.

Decrease of fossil energy consumption : -50% compared to a fertilized crop, -11%
compared to a 5-year rotation without legume.

Decrease of weeds and soil-borne pathogens in a crop sequence including a legume crop compared to cereal- and oilseed rape-based crop sequences, at field scale,
allowing a reduction in pesticide use

Contribution to increase of planned biodiversity in the landscape ➔ decrease of
insect pest populations with aerial dispersal on main arable crops

Key role in the associated biodiversity whether in the air
(pollinators on faba beans,
alfalfa, clovers; Tasei 1978, 1984) or in the soil microflora

Question 5

Why this ‘legume paradox’ ?

Answer 5

low yield due to the cost of protein 
synthesis
Increasing gap between pea and wheat 
yields due to the higher sensitivity of grain 
legumes to climatic stress (heat, water, 
frost) more frequent in recent years.
 Yield more variable than other main
arable crops

Economic return on following crops is rarely considered
Pea has generally the lowest gross margin among
arable crops
• But the crops following a pea have the highest gross
margin
• ➔ the economic interest of the legume crop should
be assessed at the scale of the crop sequence

A lack of advice on legumes
Multi-year recommendations are not available
• The environmental benefits of legumes are rarely known and
thus not taken into account by farmers,extensions, and users.

Question 6

explain the principle about Rhizobia and nitrogen fixation.

Answer 6

there is 79 percent of nitrogen in the air but the plants cannot be used directly by most of the plants. only legumes are capable of converting the nitrogen from the air into compounds that are useful for them. This is the result of symbiotic relationship between the legumes and the root-nodulating bacteria known as Rhizobia.
the roots in the nodules are full of rhizobia. The plants feed the bacteria with energy in the form of energy and the bacteria coverts the nitrogen in the air into ammonium that is used by the plants for synthesis of amino acids in the root nodules.

each legumes has specific rhizobia and often not present in the soil. therefore the bacteria is introduced by inoculation before the sowing of the seeds or transplantation by inoculating in rhizobium medium.