Nitrogen rates on the agronomic performance of second-crop corn single and intercropped with ruzigrass or showy rattlebox

Abstract

Topdressing nitrogen (N) rates may alter the second-crop corn performance, and this response may vary if the corn is grown single or intercropped with grass or leguminous species. This study aimed to evaluate the effect of topdressing N rates on the growth and productive performance of second-crop corn grown single or intercropped with ruzigrass (Urochloa ruziziensis) or showy rattlebox (Crotalaria spectabilis). The experiment was carried out in a randomized block design, with a split-plot arrangement and four replications. The plots consisted of corn grown single or intercropped with ruzigrass or showy rattlebox, while the subplots consisted of N rates (0, 60, 120, 180 and 240 kg ha-1). The evaluated variables were: SPAD index at R1; normalized difference vegetation index at V4 and V7; leaf area at R1; leaf and total corn dry mass at R1; grain and total corn dry mass at R6; number of ears per plant and grains per ear; 1,000-grain mass; and grain yield. In the absence of N fertilization and with topdressing of 60 kg ha-1 of N, the intercropping with U. ruziziensis reduces the growth and productive performance of second-crop corn. The topdressing N fertilization for second-crop corn intercropped with U. ruziziensis minimizes the forage competition on corn growth and provides a productive performance similar to monocropping from 120 kg ha-1 of N. The intercropping with C. spectabilis does not change the corn growth and productive performance, as well as the response to the topdressing N rates, when compared to monocropping, in the second crop cultivation.

Cropping System and Nitrogen Supply Interfere in Sustainability of Maize Production in the Dry Season

“…Among the species studied in the intercropping system, the genera of Urochloa and Megathyrsus have shown large amounts of dry biomass, which is critical for residue formation in no-till farming and animal feed in the dry season. In addition, these grasses have high C/N and lignin/total N ratios, reducing the decomposition rate and protecting the soil against erosion and solar radiation action for a longer time [3][4][5]. Maize and tropical grasses are nitrogen-demanding plants, and its low availability in the soil can result in variations in their production efficiency [6].…”

Potential interaction of soybean-grass intercropping with residual nitrogen for a no-tillage system implementation

“…Choosing a suitable intercropping system for each case is quite complex, as its success depends on interactions between the species used, management practices adopted, and environmental conditions (Iqbal et al, 2019). Intercropping of maize (Zea mays) with grasses in a pasture renovation and straw production for a no-tillage system is a recent practice, which has been widely studied in Brazil (Pereira et al, 2016;Batista, Giacomini, Gerdes, Mattos, & Otsuk, 2019;Rocha et al, 2020;Sapucay et al, 2020). However, intercropping grasses with soybeans is still a challenge due to the small size of soybean plants and low competition capacity (Machado, Cecato, Comunello, Concenço, & Ceccon, 2017).…”