The effect of soil mulching with straw on the yield and selected components of nutritive value in broccoli and tomatoes

By maintaining proper moisture and reducing daily temperature fluctuations, mulching improves soil conditions for plant growth and development, resulting in a positive effect on the vegetable yield. The chemical composition of vegetables is genetically determined as well as being modified by factors affecting the plant during growth, and particularly climatic conditions and agro-technology practices. The effects of soil mulching with rye, corn, rape and buckwheat straw at a dose of 10 and 20 t ha^-1 on the yield and changes of selected components of nutritive value in ‘Milady’ F₁ broccoli and ‘Polfast’ F₁ tomato were investigated. The effect of straw was compared to a control plot without mulch. The yield of the vegetables and their chemical composition depended to a higher degree on weather conditions in the years of study. 2010 was the most favourable for broccoli yielding and 2011 for tomato. More nutrients components in heads and fruits were found in 2011 and 2012, which were characterised by favourable rainfall distribution. All straws applied in the experiment, irrespective of dosage, caused an increase in broccoli yield. However, soil mulching with straw at a dose of 10 t ha^-1 was better for tomato yielding. Soil mulching with rye, corn and buckwheat straw increased the share of marketable yield in the total yield of broccoli and rye straw as well as the share of marketable yield of tomato. Mulching with rape and buckwheat straw decreased dry matter content in the edible parts of the vegetables. Mulch with rye straw contributed to a decreased content of ascorbic acid in heads and fruits and also caused a slight reduction in tomato flesh acidity. However, soil mulching with corn and rape straw caused an increase in total sugars and monosaccharide content in broccoli and tomato.