Application of nano cow manure compared to common chemical and cow fertilizers on saffron yield and some soil characteristics

Cow manure is one of the most commonly used fertilizers in saffron cultivation, but its main problem is the slow process of decomposition and the slow release of nutrients in the short term; leading to over use of chemical fertilizers by farmers. It is expected that with the introduction of nanotechnology in the field of agriculture, a suitable solution will be found to improve the absorption time of organic fertilizers. Cattle manure nanoparticles can reduce the decomposition time of cattle manure with higher specific surface area. Therefore, a split-plot design was carried out using two conventional methods of mulching and mixing with soil on the performance of saffron and soil characteristics to compare the performance of conventional chemical fertilizers and cow manure with nano cow manure.The main factor in seven levels (including nano cow manure in two amounts of five and 20 tons per hectare and in two forms of application of mulch and mixed with soil, normal cow manure in the amount of 20 tons per hectare and in two forms of mulch and mixed with soil and no use cow manure) and the sub-factor included NPK chemical fertilizer (at two levels of use and non-use). The results showed that by making cattle manure nanosized, its half-life in the soil decreased from about 36 weeks to 11 weeks. Nano cow manure treatment of 20 tons per hectare mixed with soil showed an increase in dry stigma yield by 43.7, 46 and 57%, respectively, compared to conventional cow manure treatments, chemical fertilizer treatments, and controls. The nano application of cow manure resulted in maintaining more moisture, less mechanical resistance in the soil, and more percentage of nutrients in the plant. In the comparison of the two methods of mulching and mixing, it was observed that in the mulching method, the amount of moisture is higher and the surface mechanical resistance is lower in the soil, and in the mixing method, the amount of nutrients in the leaves is higher. The results showed that in treatments with nano cow manure, the mixed method is preferable to mulch. By making cattle manure nano, using the mixed method instead of mulch and applying higher levels of cattle manure, was reduced the synergistic effect of chemical fertilizers in increasing yield. As in nano cow manure treatment (20 tons per hectare mixed with soil) was not observed significant yield increase due to the addition of chemical fertilizer. Also, nano cow manuew five ton per hectare treatments (mulch and mixture) showed a 22% yield increase compared to conventional cow manure treatments. It is possible to increase the yield by 22% by making cow manure nanosized, along with reducing the consumption of cow manure by 75% in the second year of saffron cultivation.