Productivity assessment of maize (Zea mays L.) and soybean (Glycine max L.) cropping systems in Laguna and Nueva Ecija, Philippines

Intercropping and relay cropping can increase nutrient use efficiency ((NUE), land equivalent ratio (LER) and net income per unit area of land. The relay cropping and intercropping were performed at Laguna and Nueva Ecija, respectively with five cropping systems: monocrop maize (M), monocrop soybean (S), maize-soybean intercropped or relay cropped (M+S or S/M), soybean with Rhizobium (SwR), and maize-soybean with Rhizobium inoculant intercropped or relay cropped (M+SwR or SwR/M), and two tillage systems: conventional tillage (CT) and reduce tillage (RT). The said two provinces have specific cropping system viz. either relay or intercropping to assess its influence on the test species agronomic performance and economic profitability. In Laguna, plant height, biomass partitioning for ear, 1000-seed weight, and grain yield of maize all increased in monocropping. Uninoculated soybean relayed with maize increased plant height of maize at maturity and Rhizobium inoculant did not influence the grain yield and yield components of maize. In soybean, S and SwR had increased 1000-seed weight than relay cropping. However, combined crops (soybean/maize) had the highest NUE, gross income and net income with LER of 1.58. Relay cropping conducted in Laguna maximize total productivity per unit area and with dual purpose of ensuring food and nutritional security from two crops harvested at the same plot. In Nueva Ecija, M in plant height, number of kernels per ear, ear weight per plant, and maize grain yield all increased. In sybean, harvest index increased in monocropping among cropping systems. In this latter study, monocropping resulted in higher yields compared to having soybean and maize intercrop. However, this yield advantage is not necessarily translated as an advantage in economic terms. Further, studies on cropping systems to explore the best combination of crops to improve the mutualism between crops for increasing yield of the main crop and additional crop for the benefit of the farmers. Moreover, total NUE of combined crops (maize+soybean), gross income and net income all increased with LER of 1.70. The identified advantages in the use efficiency of land, nitrogen use efficiency and net income are essential, however, obtaining such yield benefits in actual in the Philippine agriculture will require site-specific technology and training for the farmers.