Soil chemical quality changes and implications for fertilizer management after 11 years of no‐tillage wheat production systems in semiarid Morocco

Abstract

A long-term experiment comparing no-till with conventional tillage systems across ®ve rotations was evaluated 11 years after initiation. The objectives of the present paper are (1) to report differences in soil chemical properties (namely soil organic matter, total nitrogen, phosphorus, potassium and pH) that have resulted by converting from conventional to no-till under contrasting cropping systems and (2) to draw tentative conclusions and recommendations on fertility status and fertilizer use and management. Soil in the no-till system had increased surface soil organic C levels relative to conventional tillage regardless of rotation. In addition, depending on the rotation, the N and P content of the soil improved with no-till compared with conventional tillage. In other words, no-till has helped to retain soil organic matter (SOM), conserved more N, and resulted in increased extractable P and exchangeable K concentrations in the upper root-zone. Hence, wheat produced in a no-till system may receive more nutrients from decomposition of SOM and acidi®cation of the seed zone. It is possible that lesser amounts of fertilizer nutrients will be needed because of the greater ef®ciency of nutrient cycling in no-till systems relative to conventional systems.

Carbon sequestration in soils of central Asia

“…Several experiments conducted in northwest Africa have demonstrated the positive effects of conservation tillage systems on enhancement of the SOC pool (Mrabet, 2000;Mrabet and Franzluebbers, 2002;Mrabet et al, 2001aMrabet et al, , 2001bBessam et al, 2001;Saber and Mrabet, 2002). The data in Table IV from semiarid regions of Morocco show a SOC sequestration rate of 305 kg C ha À1 y À1 upon conversion from plow tillage to no tillage, and 102 to 270 kg C ha À1 y À1 upon adoption of continuous cropping, which including forages/legumes in the rotation cycle (Mrabet et al, 2001a(Mrabet et al, , 2001b. Bessam and Mrabet (2003) reported that after four years of no-till an extra 5Á6 Mg ha À1 of SOC was sequestered in the 0-25 cm layer, and after 11 years the SOC pool increased further to Reizvikh and West (1995) 7Á21 Mg ha À1 .…”

Effect of Compost Made with Sludge and Organic Residues on Soil and Sugar Beet Crop in Morocco

“…Significant declines in soil organic matter lead to the deterioration of its physical properties and imbalances in its mineral content (Mustin, 1987;Mrabet et al, 2001). In addition, application of conventional agricultural practices such as deep soil tillage, can lead to a progressive deterioration of soil fertility, especially in Mediterranean areas characterized by scarce rains and elevated temperatures (Biederbeck et al, 1994;Bulluck et al, 2002;Moussadek et al, 2014).…”

Tillage System Affects Soil Organic Carbon Storage and Quality in Central Morocco

“…The decline of SOM in cultivated soil of Morocco, due to the tillage intensification, decreased soil quality and increased the risk of soil degradation [11,12]. In fact, FAO estimated that 71% of Moroccan agricultural soils are degraded and require conservation measures [8].…”