Documenting of crop managements affecting on rice production (Oryza sativa L.) in Guilan province

In order to document effective crop managements on rice production and yield in Guilan province, a field experiment was carried out during two years 2018 and 2019. So, that the effect of management factors applied (seedling age, transplanting date, planting density, planting method, amount of nitrogen fertilizer and irrigation volume) by the farmers of three counties of Sangar, Khoshkebijar and Kouchesfahan on rice yield and yield components was investigated. Therefore, 36 farms were selected in the mentioned counties that represented the management in the entire province. The results showed that the highest yield of paddy with an average of 4500 kg.ha-1 was recorded for the two villages of Jorkuye Khoshkebijar and Ebrahimsara Kouchsefahan, and the lowest grain yield was related to the village of Gilvadashtan Kouchsefahan with an average of 3000 kg.ha-1. The reason for the high yield in the fields is related to the timely planting dates, transplanting with the suitable age, optimal plant density per m2, more soil organic carbon and the appropriate amount of nitrogen fertilizer used, which shows the impact of the crop management and soil characteristics on yield. Among all management factors, timely planting can be introduced as the most important management component of rice cultivation in the province. So that suitable weather conditions in timely planting dates, especially during flowering and seed filling, led to the use of appropriate temperature for a longer time and to take advantage of all the environmental and management factors that led to higher grain yield.