Chickpea grains are a good source of many essential mineral nutrients, protein, and dietary fiber and are low in saturated fat (http://ndb.nal.usda.gov/ndb/foods/show/4778). The chickpea crop helps to restore and maintain soil fertility through symbiotic nitrogen fixation.
Further, to maintain soil fertility, castor bean cultivation with nitrogen inputs is necessary.
I maintain soil fertility by each year sprinkling a nitrogen-rich fertilizer on the ground, then topping it with a one-inch blanket of compost.
Scientists believe the worms could help maintain soil structure and nutrients because they eat a different nitrogen and carbon faction of soil.
Legumes, which fix nitrogen to the soil, were also grown; they helped to maintain soil health and added plant protein to the diet.
Plants grown under drained soil were watered daily to maintain soil humidity at field capacity.
This will help, in part, to maintain soil fertility.
Referring to the kind of digestate, the following credits were determined: substitution of mineral fertilizer (nitrogen, phosphorus, potassium), substitution of peat (only in case of finished compost), humus accumulation (carbon-sink), and humus reproduction (i.e., for maintaining soil fertility).
This indicated that QPM maintains quality even under low soil nitrogen, a widespread condition in Africa.
Even if a proportion of soil nitrogen is fixed from the air, this is not sufficient to maintain agricultural productivity and requires external addition of fertilizers.
