Effect of Rice Straw and Applications of Potassium Silicate, Potassium Humate and Seaweed Extract on Growth and Some Macronutrients of Sweet Pepper Plants Under Irrigation Deficit

Abstract

Field experiment was conducted during the two growing seasons of 2013-2014 and 2014-2015, in a private farm at El-Salheya El-Gedida City, Ismailia Governorate, Egypt, to investigate the effect of rice straw (RS) as alternative to sandy soil (SS) and drenching applications of potassium humate (K2-HA) at 2 g/l, potassium silicate (K2SiO3) at 5 g/l, and seaweed extract (SWE) at 0.5 g/l on improving growth of sweet pepper (capsicum annuum L.) plants under deficit irrigation every 2 (I2), 3 (I3) and 4 (I4) days in addition to daily irrigation (I1) as control. Plant samples were taken at 90 days after transplanting to record leaf area, shoot fresh and dry weights, in addition to, determination of leaf relative water content (LRWC), concentrations of N, P, K and Ca. Mean values of drenching applications showed significant increase in the growth parameters ;shoot fresh and dry weights, leaf area, LRWC, as well as, concentrations of N, P and Ca in the two seasons comparing to untreated control and the best results were due to K2-HA followed by SWE then K2SiO3. The highest concentration of K was obtained by K2SiO3 followed by K2-HA then SWE. Plants were grown on RS showed significant increase in LRWC comparing to plants were grown on SS. Plants were applied with I2+ K2-HA+ SS showed the highest significant value of shoot fresh weight, shoot dry weight, leaf area, N, P and Ca concentrations followed by I2+SWE+SScomparing to control plants applied with I1+ SS without drenching applications. Plants were grown on RS showed significant increase in growth parameters comparing with control plants but less than those were grown on SS. The best results were achieved by I3 + K2-HA+ RS, I3 + SWE+ RS, I4 + K2-HA+ RS. Plants were grown on rice strawunderI3 irrigation and applied with K2-HA or SWE showed significant increase in N, P and Ca concentrations, while, under I4 irrigation an increase in N and P concentrations was obtained by K2-HA.The highest concentrations of k were observed with plants grown on SS under the highest level of irrigation deficit I4 by K2SiO3.It could be concluded from the present study that rice straw could alleviate the negative effect of low water supply and applications of K2-HA and SWE are recommended for enhancing sweet pepper growth and nutrient elements uptake under water deficit conditions.

Effect of Some Soil Amendments on Fruit and Seed Yield of Sweet Pepper under Water Stress Conditions: 2-Yield and Quality Parameters

“…potassium silicate with irrigation at 80 % IWR during two seasons. Similar results with humic acid or potassium silicate as soil amendments were obtained by Youssif et al (2018) Means followed by the same letter within each column do not significantly differed using Duncan's Multiple Rang Test at the level of 5%.…”

Foliar-Applied Potassium Silicate Coupled with Plant Growth-Promoting Rhizobacteria Improves Growth, Physiology, Nutrient Uptake and Productivity of Faba Bean (Vicia faba L.) Irrigated with Saline Water in Salt-Affected Soil

“…This decline could refer to the osmotic effect of salinity on the soil nutritional imbalance, which is subsequently reflected on the metabolism and enzyme synthesis of soil microbes [ 34 ]. Exogenous application of K-silicate has a positive role in enhancing plant growth, root length, and architecture [ 28 , 35 ], which mitigates the deleterious effect of salinity in the faba bean rhizosphere leading to increasing microbial biomass, which indirectly reflecting on prompting the synthesis of soil enzymes. Moreover, K-silicate could stimulate the availability of soil nutrients, such as N, which has a direct positive relationship with the activities of soil enzymes [ 36 , 37 ].…”

Collaborative Impact of Compost and Beneficial Rhizobacteria on Soil Properties, Physiological Attributes, and Productivity of Wheat Subjected to Deficit Irrigation in Salt Affected Soil

“…Compost is an organic amendment that has been decomposed through composting (residues of plant wastes) [ 25 ]. Recently, organic conditioner applications such as compost to semi-arid zones can be used to combat the harmful impacts of soil salinity as well as water stress [ 25 , 26 ]. Consequently, compost application is considered a successful agricultural strategy that improves the soil structure [ 27 ] and water holding capacity [ 28 ] as well as augments the soil nutrient availability [ 29 ], soil enzyme activity [ 30 ], and soil physicochemical characteristics under harsh environmental conditions [ 31 ].…”