DRY MATTER ACCUMULATION AND NITROGEN CONCENTRATION IN FORAGE AND GRAIN MAIZE IN DRYLAND AREAS UNDER DIFFERENT SOIL AMENDMENTS

Abstract

Soil amendment plays significant role in improving soil fertility and increasing crop productivity in rain–fed agriculture. Understanding the grain yield associated with dry matter and N concentration is essential for improving maize production. A 3– year field study was conducted to determine dry matter accumulation, nitrogen concentration and grain yield of forage and grain maize under different soil amendments in the Western Loess Plateau of China. The experiment was conducted using a randomized complete block design with four treatments and three replicates per treatment. Results showed that dry matter accumulation and nitrogen concentration in the swine manure in combination with chemical fertilized (SC) crops was significantly higher (by ≈ 60% and 39%) than no amendment (NA) which therefore translated into increased grain yield ≈ 74%. The SC treatment also improved leaf area index and chlorophyll content (P < 0.05) by approximately 34% to 32% compared to NA, which supported the above results. The nitrogen concentration in the leaf was higher at jointing and lower at maturity. Grain yield positively correlated with dry matter accumulation and nitrogen concentration at jointing, flowering and milk stage. Dry matter accumulation and grain yield also increased in the sole swine manure (SM) and maize stover (MS) treatments, but to lesser extent than SC. Based on the improvement of dry matter accumulation, nitrogen concentration and grain yield, swine manure in combination with chemical fertilizer appears to be a better fertilization option under dryland cropping systems.