Growing nursery plants in containers usually requires the addition of fertilizer to achieve optimal growth. However, misconceptions among growers often lead them to apply quantities of fertilizers exceeding the recommended dose, resulting in nutrient runoff and increased production costs. Reducing fertilizer application is beneficial to have healthy plants and environment as well as to save on fertilizer costs. In this study, we wanted to determine the minimal level of phosphorus (P) required to grow bedding plants i.e. Lysimachia nummularia 'creeping jenny' (moneywort) and Vinca minor 'Bowles' (periwinkle) in nursery. The plants were grown within a greenhouse in a mixture of peat moss, vermiculite, and rice hulls (3:1:1 v/v) substrates and subjected to various P treatments. The treatments included single dose of 1, 3, or 6 mg/L of P, double doses of 3 or 6 mg/L of P, or a control that received 6 mg/L of P at each irrigation. The results indicated that single dose of 6 mg/L of P had similar fresh weight compared to control in both taxa. Reducing P application further to a single dose of 1 and 3 mg/L reduced fresh weight and leaf area in both groundcovers however did not reduce their stem length or physiological parameters such as Soil Plant Analysis Development (SPAD) and normalized difference vegetation index (NDVI). Phosphorus concentration in the plant tissue at maturity was lower in all treatments than control for both the taxa. During the study period, control plants received 26 times the dose of P compared to plants receiving 6 mg/L of P once. Therefore, this study outlines the possibility of reducing P fertilizer application while growing these groundcovers in nurseries for sale.

Environmental damage attributed to nitrous oxide (N2O) emissions have received widespread attention. Agricultural sources release substantial amounts of N2O into the atmosphere. However, comparative studies on the effects of different irrigation and fertilization methods, namely, drip fertigation (a combination of fertilizing and irrigation), sprinkler fertigation, and traditional furrow irrigation with chemical fertilizer spraying, on N2O emissions in alkaline soil have been limited. Therefore, three-year in situ field observations were conducted to investigate the effect of these three irrigation and fertilization modes on N2O emissions using the static chamber method over the period 2015-2017. There are significant seasonal variations in soil N2O emission fluxes among alkaline soils under different fertilization and irrigation modes, with emissions peaking in July and August, but no significant difference in yearly variations. The N2O emission intensity of drip fertigation soil was 0.20 kg N t-1 year-1, of sprinkler fertigation soil was 0.38 kg N t-1 year-1, respectively, while of furrow irrigation was 0.91 kg N t-1 year-1, respectively. Moisture and temperature of soil were key factors driving the observed nitrous oxide variations. Compared with traditional furrow irrigation, drip and sprinkler fertigation significantly increased potato yield and decreased N2O emissions in alkaline soil, thus satisfying both yield and environmental protection.