The effect of alkazot, supplemental irrigation and nitrogen treatments on quantity and quality of wheat (Triticum aestivum L.)

Wheat is considered a strategic crop that provides food for half of the world's population. Therefore, increasing wheat yield per unit area seems necessary due to the limited area of cultivation. Nitrogen is an essential mineral element in plant tissues, which is necessary for plant growth and metabolic processes. In the lack of nitrogen, the plant is unable to complete a normal life cycle. Nitrogen deficiency in plants will lead to slow or stopping growth, chlorosis and necrotic spots. Basically, biofertilizers not only increase yield of the crops, rather, they affect the effectiveness of most chemical fertilizers. Also, the use of supplemental irrigation increases crop yield and improves water use efficiency. So, research on increasing wheat yield per unit area will be necessary. The purpose of this study was to evaluate the effect of supplementary irrigation, alkazot biofertilizer and nitrogen fertilizer on the qualitative and quantitative characteristics of wheat.

This experiment was carried out as factorial based on randomized complete block design with three replications at the research farm of Gonbad Kavous University in growing season during 2016-2017. Alkazot biofertilizer in two levels of non-consumption and 100 kg ha-1 and into brush seed and nitrogen fertilizer in four levels of non-application and application of 50, 100 and 150 kg per hectare as first factor and supplemental irrigation in two levels (non-irrigation and irrigation in seed filling stage) as second factor. In this study, the Gonbad cultivar of wheat was used. Planting and harvesting dates were December 25, 2016 and June 1, 2017, respectively. In the present study, half of nitrogen fertilizer and biological fertilizer were applied in sowing date. The rest of the nitrogen fertilizer was applied after emergence of spikes before rainfall. In this study, the measured traits included plant height, number of spikes per square meter, number of seeds per spike, 1000-grain weight, grain yield, protein percentage and protein yield.

In the present experiment, alkazot fertilizer significantly affected plant height, number of grain per spike, 1000-grain weight, grain yield, protein percentage and yield. Overall, all of these traits under application treatment of alkazot fertilizer were more than non-application treatment with value of 4.16, 8.11, 12.04, 21.72, 3.74 and 26.40%, respectively. Supplemental irrigation also significantly affected 1000- grain weight, grain yield, protein percentages and yield. 1000-grain weight, grain yield, protein percentage and protein yield in irrigation treatment was 37.35 g, 5103 kg ha-1, 14.40% and 739.8 kg ha-1, respectively. In contrast, in non-irrigation treatment the amounts of these traits were 29.4g, 3787 kg ha-1, 15.00% and 573.8 kg ha-1, respectively. Effect of nitrogen on plant height, number of spikes per square meter, number of seeds per spike, 1000-grain weight, grain yield, protein percentage and yield were significant. Plant height, spikes per square meter, grain per spike, 1000-grain weight, grain yield, protein percentage and yield in non-application of nitrogen was 69.62 cm, 354.6 spike, 31.3 grain, 31.63 gr, 3502 kg/ha, 14.07% and 492.1 kg ha-1, respectively. The maximum amount of plant height, spikes per square meter, grain per spike, 1000-grain weight, grain yield, protein percentage and yield with value of 73.95 cm, 440.4 spike, 35.74 grain, 34.59 gr, 5364 kg ha-1, 15.54% and 831.8 kg ha-1 belonged to application of 150 kg N ha-1, respectively.

According to the results, 150 and 100 kg per hectare of nitrogen had a significant effect on all measured traits of wheat cultivar except grain per spike in case of alkazot biofertilizer. While irrigation in reproductive stage affected just 1000-grain weight, seed yield, protein percentage and yield. According to the results, it can be concluded that the amount of rainfall and temperature at the time of vegetative growth in Gonbad Kavous County was sufficient that in the reproductive stage, once supplementary irrigation with the use of alkazot and nitrogen resulted in good quantitative and qualitative yield.