Peat is a spongy substance which is an effect of incomplete decomposition of plant residues in different stages of decomposition. Between the several organic matters which are used as substrate for horticultural plants cultivation in soilless conditions, peat is the unabandonable ingredient for mixtures for commercial production of plants. Peat is used in horticulture as a component of garden plant substrates, in agriculture for the production of garden soil and as an organic fertilizer, and in balneology as a material for baths and wraps. The use of peat for agriculture and horticulture is determined by the following quality parameters: the degree of decomposition, ash content, pH, the presence of carbonates, the density of the solid phase, bulk density, and porosity. As an organic material, the peat forms in the acidic, waterlogged, and sterile conditions of fens and bogs. The conditions seem like the development of mosses. The plants do not compose as they die. Instead of this, the organic matter is laid down and accumulates in a slow time as peat due to the oxygen deficiency in the bog. This makes peat a highly productive growing medium. In the present novel review, we discuss the peat use in horticulture.

The effect of organic amendment applications on some agrophysiological properties of pot-grown spinach was investigated under drought stress. The I1, I2, I3, and I4 irrigation treatments received water amounts up to 100, 80, 60, and 40 percent of evaporation from a reduced pan, respectively. A liquid organic amendment was applied to spinach seeds as seed treatment at the ratios of 0.1 percent (H1) and 0.2 percent (H3). Furthermore, in the H2 and H4 treatments the amendment was foliar applied to spinach seedlings at the ratios of 0.1 percent and 0.2 percent in addition to the seed treatments, respectively. Organic amendment treatments positively affected root and leaf growth. The plants responded to water stress by lower growth. Leaf relative water content, membrane permeability, chlorophyll reading, and stomatal conductance values also indicated significant changes. These results support the view that organic amendment application increased growth. However, it could not provide a significant contribution for growth under water stress.

Günümüzde artan sanayileşme ve kentleşme ile beraber çeşitli çevre kirlilikleri artmış ve birçok çevresel problem ortaya çıkmıştır. Bu problemlerin başında gelen ağır metaller, hava, toprak ve su kaynaklarında kirliliklere neden olmaktadırlar. Bitki fizyolojisini olumsuz etkileyerek, bitkisel üretimin azalmasına neden olan ağır metaller, besin zinciri yoluyla canlı sağlığını da tehdit ederler. Ağır metallerin toprağa ve bitkiye etkisi, toprak ve bitki özelliklerine göre değişiklik gösterebilmektedir. Ağır metaller toprak biyolojisinin bozulmasına, bitkide protein sentezi, DNA, RNA, kök-su ilişkisi, çimlenme, gelişme ve fotosentezin olumsuz etkilenmesine, toprak, bitki ve suda kompleks yapılar oluşturarak doku ve organların zarar görmesine neden olabilirler. Bu nedenlerle ağır metallerin toprak, bitki, su ve insan sağlığı üzerindeki etkisi tam olarak anlaşılmalıdır. Bu derlemede; ağır metallerin ortaya çıkışı, toprağa-suya etkisi ve toprak özelliklerinin ağır metallerle olan ilişkisi, ağır metallerin bitki fizyolojisine etkisi ve bitkinin ağır metallere karşı savunma ve tolerans mekanizmaları ile ağır metallerin insan sağlığı üzerindeki etkileri irdelenmeye çalışılmıştır.