T. Shobha Rani, Ch. Ramulu, T. Sukruth Kumar and R. Uma Reddy
Abstract
The rapidly emerging fertilizer Dhaincha and Sun hemp used as green manure has wide applications for use. However there have been limited studies on superior genotypes identification and effects on soil physiochemical properties after its decay. In this study, 13 Sunhemp and 17 Dhaincha accessions (developed at ARS Nathnaipally) were studied for Green manuring traits and soil chemical properties. Sun hemp and Dhaincha accessions to be screened were decomposed in a fixed plot through a randomized block field design with two green-manure-specific varieties as the controls for four seasons from kharif 2020 to kharif 2023. The contents of available nitrogen, soil organic carbon and soil pH from the initial and final samples after degradation were measured. Along with soil properties, greenmanuring traits were also recorded. There were substantial differences in the greenmanuring traits and cumulative effect of soil chemical properties among the different lines after 30 days of rolling. This study revealed in four seasons of evaluation, NTPD 13-02 and NTPD 16-02 recorded highest pH decrease in Dhaincha. Highest improvement in organic carbon observed in NTPD 13-02 and NTPD 14-02 of Dhaincha and NTPSH 11-02, NTPSH 05-02 and NTPSH 04-02 of Sunhemp. Similarly, available nitrogen was highest in NTPD 04-02 and NTPD 08-02 in Dhaincha and NTPSH 11-02 and NTPSH 08-02 in Sun hemp. These entries were more effective than two check varieties, which can be used as excellent types of breeding lines to promote the breeding of green manure crops Dhaincha and Sunhemp.