A pot study was conducted during kharif, 2018-19 in College of Agriculture, Rajendranagar, PJTSAU, Hyderabad, with the aim to evaluate the response of maize to different levels of zeolite and nitrogen and to know the influence of zeolite on selected soil properties. The treatments consists of combinations of 3 levels of nitrogen (100, 150, 200 kg ha-1) and 4 levels of zeolite (0, 2.5, 5, 7.5 t ha-1) along with a control in which only P and K were applied and they were replicated thrice in a factorial completely randomized design. Results indicated that application of zeolite (7.5 t ha-1) and nitrogen (200 kg ha-1) individually had significant effect on N, P, K contents in maize at 30, 60, 90 DAS and at harvest. N and P contents in maize was significantly higher in N200Z7.5 (Nitrogen @ 200 kg ha-1 + Zeolite @ 7.5 t ha-1) however, there was no significant interaction with respect to K content. At harvest, the available P and K were significantly higher in the treatment receiving N100Z7.5.

Imbalanced use of fertilizers for agricultural production has now become a global concern. As a result, studies on how to use efficient methods to reduce nutrient applications at the same time increasing or maintaining crop yield, reducing nutrient losses and improving nutrient use efficiency are imperative. Accordingly, a pot study was conducted to evaluate whether zeolite application might improve selected soil properties, nitrogen use efficiency during maize cultivation. Among all treatments, irrespective of the nitrogen level, NUE (N recovery and agronomic use efficiency of N) showed an increasing trend with the increase of zeolite levels, nitrogen levels and their combination. The highest N recovery and agronomic NUE was obtained in N200Z7.5 (Nitrogen @ 200 kg ha-1 + Zeolite @ 7.5 t ha-1), was on par with N200Z5 (Nitrogen @ 200 kg ha-1 + Zeolite @ 5 t ha-1). N uptake by maize at harvest was highest in N200Z7.5 (Nitrogen @ 200 kg ha-1 + Zeolite @ 7.5 t ha-1).

The rice - maize cropping system is one of the predominant cropping systems in Telangana state, which also produces large quantities of residues, whose disposal is a major problem. A large quantity of paddy straw is burnt on the farm to clear the field for succeeding crop. On the farm, a significant amount of paddy straw is burned to prepare the land for a subsequent crop. Burning crop residue damages the air and results in the loss of a significant amount of biomass plant nutrients and the entire amount of carbon. The purpose of the study was to investigate the impact of paddy straw burning on soil biological properties (enzyme activities, microbial population) and to know the amount of green house gas (GHG) emissions released due to burning of residue, under two tillage systems viz., no tillage and conventional tillage. Results indicated that there was a significant decrease in soil microbial population, dehydrogenase activity (41.52% in NT and       40.07% in CT), acid and alkaline phosphatase activity and urease activity in soil due to residue burning. It also indicated that there was a rise in CO2, CH4 and N2O emissions 48 hours after residue burning. It can be concluded that crop residue burning leads to decrease in the enzyme activities and soil microbial population. It also leads to rise in green house gas emissions. The impact of rice straw burning on different microbial genera has to be further studied by researchers.

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An incubation study was conducted at college of agriculture, rajendranagar, PJTSAU to evaluate the influence of zeolite application on inorganic nitrogen, water soluble and exchangeable potassium in soil. Clinoptilolite Zeolite was fully mixed with soil (7.5 t ha-1) at the start of the experiment. Nitrogen was applied to soil through urea (200 kg ha-l). The experiment was conducted for 35 days and soil was analyzed for inorganic nitrogen, water soluble and exchangeable potassium at weekly intervals i.e., 1, 7, 14, 21, 28, 35 days of incubation. The results indicated that the treatment with zeolite application showed significantly higher ammoniacal nitrogen from day 1 (136.54 mg kg-l) to day 35 (38.71 mg kg-l) as well as nitrate nitrogen (day 1 – 59.13 mg kg-l; day 35 – 130.13 mg kg-l). Similarly water soluble (day 1 – 92.21 kg ha-l; day 35 – 103.13 kg ha-l) and exchangeable potassium (day 1 – 363.69 kg ha-l; day 35 – 393.94 kg ha-l) was also significantly higher in zeolite applied treatments. Thus, mixing of zeolite into soil improves inorganic nitrogen through reducing leaching losses and also improves water soluble and exchangeable potassium.