Beet-arugula intercropping under green manuring and planting density induce to agro-economic advantages

Abstract

One of the biggest challenges in the intercropping system of two crops is to obtain the optimal dose of green manure and the adequate population density of the crops. So, the objective of this work was to evaluate the performance of beet and arugula intercropping, influenced by green manuring with Merremia aegyptia and Calotropis procera and arugula population densities in two cultivation years, in semi-arid environment. The experimental design used was in randomized complete blocks, with the treatments arranged in a 4 x 4 factorial scheme, with 4 repetitions. The first factor of this scheme consisted of equitable amounts of M. aegyptia and C. procera biomass (20, 35, 50 and 65 t ha-1 on a dry basis) and the second factor, by arugula population densities (40, 60, 80 and 100% of the recommended density for single cropping, corresponding to 400, 600, 800 and 1,000 thousand arugula plants ha-1). The production and its components were evaluated on beet and arugula. In addition to these characteristics, the following agro-economic indicators were also determined for each treatment: system productivity index (SPI), land equivalent coefficient (LEC) and monetary equivalent ratio (MER). The greatest agro-economic advantages of the beet with arugula intercropping were achieved with a system productivity index (SPI) of 53.47 t ha-1, land equivalent coefficient (LEC) of 0.84 and a monetary equivalent ratio (MER) of 1.56, respectively, combining 65 t ha-1 of M. aegyptia and C. procera biomass with the arugula population density of 1,000 thousand plants ha-1. The maximum optimized commercial productivity of beetroots in the system intercropped with arugula was 23.20 t ha-1 using 65 t ha-1 of M. aegyptia and C. procera and in the arugula population density of 1,000 thousand plants ha-1, while the maximum arugula productivity intercropped with beet was 9.65 t ha-1, in the same combination of green manures amount and arugula population density.

Maximizing agro-bioeconomic benefits in intercropped systems of radish and lettuce in the semi-arid environment

“…The positive values of the aggressivity of radish over lettuce in the intercropping indicate that this tuberose was the dominant crop in the system and more competitive as the lettuce planting density increased and the amount of green manure decreased. A similar result was obtained by Sá et al (2021), when intercropping radish with arugula in different doses of organic fertilizers and diverse leafy crop populations, obtained positive values of the radish aggressiveness over the leafy crop, indicating that this tuberose was the dominant crop in the system. This behavior can be attributed to factors related to the morphology, physiology, and nutritional needs of the crop.…”

“…Opposite behavior was recorded for the actual yield loss (AYL), where it increased with the increase in the amounts of green manures applied and with the increase in the population densities of lettuce, reaching a maximum value of 2.40 in the combination of 65 Mg ha -1 of the green manures incorporated into the soil and 300 thousand lettuce plants per hectare (Figure 2D). This result was superior to that of Sá et al (2021) when intercropping radish with arugula under green manure and population densities, reaching an AYL value of 1.31. This AYL value, much higher than 1, resulting from the increase in the amounts of green manures and the population densities of lettuce, positively influenced the intra and interspecific competition of radish and lettuce crops, resulting from the better use of environmental resources, providing more advantageous intercrops than their monocrops.…”

“…g) The actual yield loss (AYL) of the intercropped system was determined by the expression used by Silva et al (2021):…”

“…Another requirement for the success of this cultivation practice has been how to properly manage production factors, types and amounts of fertilizers, and planting density of the component crops (Andrade Filho et al, 2020). Among the types of fertilizers that stand out are green manures, such as hairy woodrose and roostertree, which are spontaneous species from the Caatinga biome (Lino et al, 2021;Sá et al, 2021). The hairy woodrose is an herbaceous species with an average production of green and dry phytomass around 36,000 and 4,000 kg ha -1 , respectively, with high nitrogen content, around 26.2 g kg -1 in dry matter, and a C/N ratio of 18/1 (Linhares et al, 2012).…”

Effects of different planting distances and fertilizer use on remediation of cadmium contaminated farmland by intercropping of Pumpkin and amaranth hypochondriacus L.

“…These results indicated that although amaranth seeds limited the spread and growth of pumpkin stems and leaves during intercropping, due to the existence of intercropping effect, appropriate planting density of amaranth seeds could keep pumpkin yield basically stable. And it is similar to the study by Lino et al(2021), the high population density of arugula caused a certain degree of resource competition pressure on the beet intercropping system, but almost had no negative impact on its yield.…”