id	author	title	date	pages	extension	mime	words	sentence	flesch	summary	cache	txt
american_scientific_journal-4816	A. Salih, Elsir; A. Elias, Neama	Assessment of Major Environmental Constraints of Riverside Cultivation in Omdurman (Sudan) by Use of Local Knowledge	2019	16	.pdf	application/pdf	6750	375	57	A wide range of naturally occurring biotic and abiotic constraints, including poor soils, water scarcity, crop pests/diseases/weeds, and unsuitable temperatures, are well-known to reduce the productivity of food crops, leading to low efficiencies of input use, suppressed crop output, and ultimately reduced food security; e.g. references [1, 2, 3, 4, 5]. They believe that weeds affect crop productivity mainly through competing with crop species over water, soil nutrients and space, as well as hosting pests and reducing crop quality when mixed with harvest.	cache/american_scientific_journal-4816.pdf	txt/american_scientific_journal-4816.txt