Comparing the effect of organic and chemical nutritional management and intercropping with clover on the quantity and quality of different wheat (Triticum aestivum L.) cultivars

Optimal availability of nutrients, particularly nitrogen (N), from authorized resources is one of the most important issues in organic agriculture. Intercropping forage legumes with cereal crops may be a way of providing ecological services such as providing N for companion or following crops by biological N fixation. To determine the effect of biological, chemical, and organic fertilization on the quality and quantity of ten different wheat cultivars, an experiment was conducted during two successive growing seasons. The three experimental factors (F1, F2, F3) were: mix cropping with Persian clover (Trifolium resupinatum L.) (F1: biological N fixation, as control); chemical nitrogen fertilizer (F2: 100 kg ha^-1, urea), and organic cow manure (F3: 40 t ha^-1). The vegetative growth parameters improved by F1 and F2 treatments. The F2 had the highest values of spikelet and seed number per spike, 1000-grain weight, and seed yield, followed by F1. The cv. ‘Kabul-13’ was the best among all tested cultivars in terms of almost all reproductive parameters. The highest seed yield was obtained by F2 ‘Kabul-13’ (8.02 t ha^-1), and F1 ‘Kabul-13’ (7.26 t ha^-1). By considering seed yield, ‘Chont-1’ and ‘Kabul-13’ were more suitable to be intercropped with clover. The effect of experimental factors was not significant on seed potassium and phosphorus contents, while percentage of seed protein improved by F3 (13%), and ‘Mugawim’ (13.59%). The highest protein yield was gained by F2 and F1 (820 and 650 kg ha^-1) and also by ‘Kabul-13’ (850 kg ha^-1). Overall, mixed cropping of wheat and clover can be suggested as a possible alternative for nutrients providing in wheat production in low input agro-ecosystems.