Field experiments were conducted at Viswavidyalaya farm, Jaguli, Nadia following system intensification (SI) package of practices during 2011-2016 on pre-Kharif black gram (Vigna mungo) and green gram (Vigna radiata) – Kharif direct-seeded puddled and transplanted rice (Oryza sativa) – Rabi potato (Solanum tuberosum) and onion (Allium cepa) crop sequences. Balance nutrition of N:P:K:Neem cake at recommended doses were used along with judicious water in critical crop growth stages and ecosafe green labelled pesticides for insect and disease management. For annual planning of weed pest management (APWPM), glyphosate 71 SG + oxyfluorfen 23.5 EC mixture at 1000 g/ha was used after pre- Kharif crops besides the application of selective pre-emergence (PE) organic herbicides treatment wise in different crops along with HW, post-emergence (PoE) herbicides and weedy check as standard. The results revealed that PE herbicide treatments recorded 30.5 and 10.3% more productivity over PoE herbicides treated plots and 38.4 and 60.0% over weedy check in blackgram and greengram, respectively. The corresponding values were 2.74 and 5.14% and 32.7 and 31.0% in direct seeded puddled and transplanted rice, respectively. In Rabi potato and onion, these figures were 21.1 and 30.4% and 42.0 and 49.0%, respectively. The soil microflora population at harvest recorded increasing in all PE herbicide used plots though an initial decreasing trend upto a month.