Abstract

                                To evaluate the effect of different cropping sequences on soil nutrients status, nutrients uptake and crop yield in PAP command area an experiment was carried out at Coconut Research Station, Aliyar Nagar, Pollachi during 2017-18. In Kharif season, the rice crop was grown followed by seven sequential crops during rabi season. Thus, there were seven different cropping sequences viz., Rice – Sunflower (T₁), Rice – Sesame (T₂), Rice – Blackgram (T₃), Rice – Castor (T₄), Rice – Maize (T₅), Rice – Onion (T₆) and Rice – Groundnut (T₇) cropping sequences. Results of the post - harvest soils of the different cropping sequences revealed that significantly highest soil organic carbon SOC content was observed in Rice – Groundnut (T₇) cropping sequence, however this was on par with Rice – Maize (T₅) and Rice – Castor (T₄) cropping sequences. A significant higher value of available P was registered in Rice – Blackgram (T₃) cropping sequence that was on par with Rice – Groundnut (T₇) cropping sequence. Available K was significantly higher in Rice – Groundnut (T₇) cropping sequence which was on par with Rice – Onion (T₆) cropping sequence. The Rice – Maize (T₅) cropping sequence recorded the highest total N uptake and Rice – Sunflower (T₁) cropping sequence registered higher total P uptake and the total K uptake was higher in Rice – Maize (T₅) and Rice – Sunflower (T₁) cropping sequences. Grain yield and straw yield were significantly higher under Rice – Maize (T₅) and Rice – Groundnut (T₇) cropping sequences. Though the Rice – Castor (T₄) cropping sequence recorded highest B:C ratio of 2.08, considering the quantity of water consumption, economic yield, soil nutrients and B:C ratio, the best cropping sequence registered in Parambikulam Aliyar command area was Rice – Castor (T₄) cropping sequence followed by Rice – Groundnut (T₇) and Rice – Maize (T₅) cropping sequences.

Key words : Cropping sequence, Nutrient dynamics, Nutrient uptake, Grain and Straw yield.