Sentence:  We should think "him" a very "imprudent Husbandman", that to save a "little seed" at present, would "sow so thin", as to spoil his crop. And the "same folly" 'twill be in us, if by the "sparingness" and "niggardize" of our "Almes", we make our selves "a <WSD>lank</WSD> Harvest" hereafter, and lose the "reward" God hath provided for the "liberal" Almes-giver. 
Meaning of the word marked with <WSD> tags:  Meagre, paltry, scant in quantity.