Mixed Cropping as Affected by Phosphorus and Water Supply

Abstract

In a future exposed to threats of climate change, sustainable biomass production will be crucial. Maize (Zea mays) and sorghum (Sorghum sp.) are important crops for human and animal nutrition, as well as for bioenergy. The aim of this study was to investigate maize and sorghum in mixed cropping with soybean (Glycine max) and faba bean (Vicia faba) regarding biomass yield, drought tolerance, phosphorus (P) availability, and enzyme activity in soil as affected by the single and combined effects of water and P supply in two outdoor pot trials with rainout shelters. Maize had the highest biomass under sufficient water supply (80% water holding capacity, WHC), but a sharp decrease of its biomass of about 60% was measured when water was limited (30% WHC). In the mixtures, drought induced reduction of biomass was less than 40%. For mixed cropping usually higher contents of labile P fractions in soil than for sole cropped monocots were found. This was especially true for the combined stress of water and P deficit and can be partly explained by a higher activity of the acid phosphatase in the soil of the mixtures. A higher yield stability of the crop mixtures makes them a suitable agronomic alternative to sole cropped maize or sorghum under suboptimal conditions of water and P shortage.

The Comparison of Soil Agrochemical and Biological Properties in the Multi-Cropping Farming Systems

“…The available phosphorus also depends on the organic matter content in the soil [ 38 ]. In the presence of available phosphorus deficiency and drought conditions, it has been observed that crops grown in mixtures absorb phosphorus released in the soil from leguminous plants directly, thus allowing for plant resilience [ 39 ]. In addition, the availability of organic phosphorus is also increased by a variety of leguminous crops.…”

Bioenergy Crops: Current Status and Future Prospects

“…Even though intercropping has a long agronomic tradition in maintaining soil health and improving crop health and performance, the technique should further be employed for a sustainable biomass production allowing, for example, the reduction of nitrogen fertilizers when employing nitrogen-fixing legumes. Intercropping maize and sorghum (Sorghum bicolor L.) with legumes reduced the adverse effects of drought stress and phosphorous deficiency, as demonstrated in an outdoor pot trial by Eichler-Löbermann et al [9]. Under suboptimal conditions of water and phosphorous shortage a higher yield stability of the crop mixtures was demonstrated, which makes them a suitable agronomic alternative to sole cropped maize or sorghum.…”