Effects of fertilization and irrigation on productivity, plant nutrient contents and soil nutrients in southern Mongolia

Abstract

The study attempts to evaluate the effect of fertilization and irrigation on steppe productivity in dry southern Mongolian desert-steppes. We conducted an irrigation-and NPK fertilization experiment, irrigating at levels of +100 mm and fertilizers at amounts equivalent to 20 gN (m² year) −1 in a factorial design. We tested the effects on soil nutrients and biomass production. Nutrients in plant tissue were analysed for Stipa krylovii and S. gobica, and for mixed subsamples of total above-and belowground biomass. Available P and K and total K increased in the soil after fertilization while irrigation reduced total N. Biomass yield almost tripled and inflorescence numbers increased by factors of 4-8 due to fertilization while irrigation alone had very restricted effects and only increased biomass of Agropyron cristatum. Nutrient content of biomass was elevated on fertilized plots. Results indicate that steppe productivity is severely restricted by nutrient availability even under ambient precipitation levels, raising the question whether nutrient withdrawal caused by current land use practices has detrimental effects on pasture productivity. The anticipated beneficial effect of increasing water availability however could not be confirmed. Whether there is an improvement in productivity due to increasing rainfall, as predicted by some climate change models, will depend on the distribution and intensity of rain events.

Response of rhizosphere microbial community structure and diversity to heavy metal co-pollution in arable soil

“…Agricultural land activities, such as cultivation, fertilization, and irrigation, were the important impetus of microbial community dynamics and physiochemical phenomenon (Gupta and Germida 1988;Ronnenberg and Wesche 2011). On the basis of the influence of those practices, two completely different types of farming land (RF and PF) were selected in field condition.…”

Legacy effects of historical grazing affect the response of vegetation dynamics to water and nitrogen addition in semi‐arid steppe

“…Precipitation and N availability are the primary limitations to productivity, affecting plant species composition in grassland ecosystems (Hooper & Johnson, ). The interactive effects of N and water availability on plant growth were investigated in grasslands such as desert steppe, temperate steppe (Chen, Hooper, & Lin, ; Ren et al., ; Ronnenberg & Wesche, ) and tallgrass prairie (Smith, Schuster, & Dukes, ). Both significant interactions (Smith et al., ; Xia & Wan, ; Yang et al., ) and non‐significant interactions (Ronnenberg & Wesche, ; Wesche & Ronnenberg, ) between N addition and water availability have been reported.…”

“…The interactive effects of N and water availability on plant growth were investigated in grasslands such as desert steppe, temperate steppe (Chen, Hooper, & Lin, ; Ren et al., ; Ronnenberg & Wesche, ) and tallgrass prairie (Smith, Schuster, & Dukes, ). Both significant interactions (Smith et al., ; Xia & Wan, ; Yang et al., ) and non‐significant interactions (Ronnenberg & Wesche, ; Wesche & Ronnenberg, ) between N addition and water availability have been reported. N addition and water availability alter plant community structure and composition due to differences in N and water use strategies among species, and their interaction with abiotic conditions (Xia & Wan, ; Yang et al., ).…”

Application of a new model using productivity coupled with hydrothermal factors (PCH) for evaluating net primary productivity of grassland in southern China

“…Temporal and spatial variations were quite distinct in grassland NPP, since climatic factors, especially precipitation and temperature, were factors directly linked to periodic variations (Ronnenberg and Wesche, 2010). This study showed that a temperature rise would cause a certain level of rise in the grassland NPP in southern China, especially in the high-temperature zones.…”