Agronomic efficiencies and carbon productivity of corn-based cropping systems under Conservation Agriculture Practice Systems (CAPS) in Northern Mindanao [Philippines]

In Northern Mindanao, the sloping uplands are considered to be the last remaining frontiers of agricultural expansion. In this ecosystem, soil erosion is prevalent and excessive, hence it is fragile, vulnerable and has delicate resource. Corn is a dominant crop grown both for food and feed. Present cropping system is counterproductive to long term sustainability. Conservation Agriculture Practice Systems (CAPS) is a tailor-fitted approach for successful adoption and implementation of Conservation Agriculture (CA). A recent agronomic innovation currently gaining ground globally and tested under local condition in a sloping upland. Its three main pillars namely: 1) continuous crop rotation 2) minimal tillage and 3) continuous ground cover were used simultaneously in various cropping systems. This study was conducted to test the viability and efficiency of CAPS locally and was established in a 23 percent sloping site. Experiment was carried out in two cropping seasons (Nov 2011-Nov 2012) utilizing five corn-based cropping systems (CS), namely: CS1 (corn + Arachis pintoi), CS2 (corn + Stylosanthes guianensis), CS3 (corn + cowpea - upland rice + cowpea), CS4 corn + rice bean) and CS5 (corn-corn), respectively. Agronomic characteristics and carbon productivity were measured among various CAPS wherein dry matter yield, grain yield and carbon productivity differed among the CAPS treatments, relative to sole corn. Higher grain yields were obtained in cropping systems under CAPS or corn intercropped, or sequenced with legume compared to the conventional (CS5) cropping system. Highest grain yield was obtained in CS2 (4.26 t/ha) while highest carbon productivity measured through dry weight was obtained in CS1 (6.76 t/ha) respectively. CS3 (13.52 t/ha) yielded the highest DMY which is significantly different from other treatments, while CS3 (7.23 t/ha) had the lowest among treatments. Viability of CAPS utilizing associated legumes and its three main pillars under a sloping upland as model is proven to be a potential option for sustainable crop production amidst climate change.