The Mutual Effect of Withholding Irrigation at Some Growth Stages and Potassium Fertilizer on Yield and Water Productivity of Wheat

Abstract

The limitation of water resources and remarkable increase in population should force research workers to find ways for saving water without significant reduction in yield. So, two field experiments were carried out at Water Management Research Station, El-Karda and Irrigation Development Area at El-Wazaria, Kafrelsheikh, Egypt, during the two growing seasons of 2013/14 and 2014/15 to study the mutual effect of withholding irrigation and potassium fertilizer on yield and water productivity of wheat. Split plot design with four replicates was used. The main plots were devoted to irrigation treatments while the subplots were assigned to potassium fertilizer. Irrigation treatments were full irrigation (W 1) including tillering (T), Jointing (J) , booting (B), heading (H) and milking (M) stage, and it has been added to a 60 cm of the root zone depth; full irrigation (W 2) including T,J,B, H and M stages, and it has been added to a 40 cm of the root zone depth; withholding irrigation (W 3) at M stage; withholding irrigation (W 4) at B stage; withholding (W 5) at J stage; withholding (W 6) at J and B stages and withholding (W 7) at J,B and M stages. All withholding irrigation treatments were irrigated to a 40 cm of the root zone depth. Potassium application treatments were 24 kg K 2 O feddan as basil along with foliar spraying twice using 2 % of potassium sulphate at 35 and 55 days after sowing and control treatment without application. Results showed that insignificant increases between full irrigation treatments of W 1 and W 2 in spike No. m-2 , spike length, kernel No. spike-1 , 1000-kernel weight, grain weight spike-1 , straw and grain yields in both seasons .No significant differences in the most of these traits were noticed among withholding irrigation treatments of W 3 , W 4 and W 5 that received four irrigation and W 1 especially in the first season that receive irrigation twice because of high rainfall.

Effect of nitrogen and potassium fertilizers on wheat productivity under different soil moisture contents

“…In this regard, Mekkei and El Haggan (2014) concluded that applying five irrigations at various wheat growth phases resulted in a larger number of spikes m -2 , whereas omitting irrigation at stem elongation, booting, or anthesis stage resulted in a lower number of spikes m -2 . These findings are consistent with those of Attia and Barsoum (2013), Rizk and Sherif (2014), Shirazi et al (2014), and Gharib and Meleha (2016). In all seasons, increasing the nitrogen rate from 50 to 90 kg N ha -1 steadily increased the number of spikes m -2 and the amount of grains spike -1 .…”

“…K application increased enzymatic activities, which likely resulted in higher nutrient mobilization in soil and plant, as well as photosynthetic translocation in plant, resulting in more spikes m -2 , grains spike -1 , and 1000-grain weight. These findings are corroborated by prior studies by El-Ashry and El-Kholy (2005), as well as Gharib and Meleha (2016).…”

“…Withholding irrigation water at different growth stages of wheat plant and irrigation based on measurements of soil moisture in several soil layers were studied by many previous researchers (Yi et al, 2013). (Gharib and Meleha, 2016) observed no significant differences between full irrigation based on the soil water content at soil layer 0-60cm (W1) and 0-40 cm (W2) in spikes number m -2 , kernels number spike -1 , 1000-kernel weight, straw yield and grain yield. They added that seasonal water applied amounted 2517 and 2025 m 3 fed -1 and water consumptive use values were 1584 and 1480 m 3 fed -1 over the two seasons for W1 and W2, respectively.…”

“…This can be partially achieved by increasing crop water use efficiency (Tari, 2016). Wheat production was increased by optimization of supplemental irrigation (Gharib and Meleha, 2016). Withholding irrigation water at different growth stages of wheat plant and irrigation based on measurements of soil moisture in several soil layers were studied by many previous researchers (Yi et al, 2013).…”

“…Li et al (2015) concluded that application of potassium improve leaf water potential, osmotic potential, turgor potential , spike length, number of grain per spike and grain yields under water stress. Gharib and Meleha (2016) discovered that applying K fertiliser reduced the detrimental impacts of not watering on yield and its components. They also stated that the application of K fertiliser had no influence on seasonal irrigation water or consumptive usage, but it boosted water productivity by boosting grain output.…”