Identifying the function of dimethylpyrazole phosphate as nitrification inhibitor in lettuce growth trials by using an agrotextile material with controlled fertilizer release property

In this study, a new agrotextile structure containing ammonium and nitrate fertilizers which is called controlled release fertilizer (CRF) was designed. The prepared structure was used in lettuce growth trials both in the absence and presence of dimethylpyrazole phosphate (DMPP) inhibitor. In order to better monitor nitrogen balance in the soil and total nitrogen amounts in the whole system including soil, plant, and agrotextile and thus revealing the efficacy of DMPP usage depending on fertilizer application type ((traditional (TF) or agrotextile (CRF)) and irrigation regime (100% and 50%), plants were harvested at three growth stages. Generally, independent of fertilizer application type, the effect of DMPP usage was more pronounced at 100% irrigation regime. Presence of DMPP and 100% irrigation in traditional fertilizer (TF) application increased soil ammonium nitrogen (NH4+-N) by 12.5% and 11.1% and decreased soil nitrate nitrogen (NO3--N) by 3.8% and 8.9% at 1st and 2nd harvest stages, respectively. DMPP usage in agrotextile (CRF) application with 100% irrigation improved NH4+-N by 353% and reduced NO3--N by 14.9% in the soil, when especially the 2nd harvest stage was considered. According to soil N results, it can be said that the DMPP usage increased the soil inorganic N content in both TF and CRF applications. But, plant N uptake results showed that the usage of DMPP either didn't change or worsen the nitrogen use efficiency in the TF and CRF applications, respectively