The agroenvironmental impact of co-utilization of red gypsum and sewage sludge was investigated. Both laboratory and greenhouse studies were conducted. The treatments were soil + sewage sludge (5% w/w) + red gypsum (0, 2.5, 5, 10, 20, and 40%, w/w). Corn was grown in the greenhouse, and the highest rate of red gypsum application was excluded. The residual calcite in red gypsum was able to increase the pH of the red gypsum-sewage sludge acidic soil system. Hence, gypsum reduced the zinc (Zn) concentrations in the soil solution released by sewage sludge. Phosphorus (P) and potassium (K) were insufficient for corn growth. At the rate of 2.5% red gypsum and 5% sewage sludge application, no dry-matter reduction was observed compared to the control. The uptake of Zn, copper (Cu), and iron (Fe) by the corn plants decreased. Therefore, co-utilization of red gypsum and sewage sludge is a better option than using these by-products separately.

Sidenuk rice is a superior rice variety produced by BATAN through a radiation mutation technique.             The new varieties that have been produced need to be supported by efforts to optimize production through fertilization technology. The purpose of this study was to determine the effect of organic fertilizer which can increase growth, production and reduce the use of urea fertilizer in lowland rice optimally. The study was conducted using a completely randomized design. Each was repeated 4 times so that the total experimental unit (pot) was 32 rice pots. The treatments include (1) Control (without urea fertilizer),              (2) Control (+) 100% urea, (3) 50% urea, (4) Local microorganisms (MOL), (5) Compost, (6) Biochar , (7) Azolla, (8) Mol + Compost + Biochar + Azola + SP 36 and KCl. The results showed that the highest grain weight was found in the 100% urea treatment, which was 43.97 g plant-1. MKBA treatment    (MOL fertilizer, compost, biochar, azolla) showed values that were not significantly different from 100% urea treatment. Organic fertilizer formula (MOL fertilizer, compost, biochar, azolla) can reduce the use of urea fertilizer by 50%.

This work investigates the effects of different soil pH and different genotypes on the nutrient profiles and in vitro digestibility of soybeans. Thirty soybean genotypes were evaluated for nutrient composition, fiber content, and in vitro digestibility after cultivation in pH 4.0 and 5.4 soils. The experiment was arranged factorially in a completely randomized block design. The experimental factors were soybean genotype and soil pH. Results showed significant (p < 0.001) differences in fiber content, non-fiber carbohydrate content, and in vitro dry matter digestibility (IVDMD) parameters among studied genotypes. There were significant differences (p < 0.05) between the two soil pH conditions for ash, organic matter, ether extract, neutral detergent fiber, acid detergent fiber, hemicellulose, and nonfiber carbohydrate. Organic matter, crude protein, ether extract, and non-fiber carbohydrate content in soil with pH 5.4

In vitro and in vivo testing for ruminant feed efficiency can be done by utilizing the stable isotope Nitrogen-15 (15N) as a tracer. Feed can be traced by labeling the forage using isotope 15N. Feed crops are labeled using an isotope 15N-enriched fertilizer. The critical thing to note is to know the content of isotopes 15N in the part of forage feed plants that have been labeled. This research aims to know the effect of urea fertilizer on the percent of atom excess 15N on corn. Corn are labeled using urea enriched with isotopes 15N in the form of urea fertilizer (10% excess atom 15N) with different doses (0-200% recommended urea dose). As a control used corn plants given urea fertilizer is not labeled 15N. The results showed that corn forage feed was successfully labeled and correlated with the dose of fertilizer. The range of atom excess 15N was 4.28 – 6.99% in corn forage. Biomass production showed no significant difference between the dose of fertilization and control, but neither protein content. Based on data, the corn forage can be used for further testing.

Mycorrhiza which plays a role in increasing P uptake of plants and also as a soil amendment to rehabilitate degraded lands. This research was conducted with the aim of isolating, characterizing, and purifying mycorrhiza from two different soil types. The results showed that the mycorrhiza species found were Glomus etunicatum, Gigaspora margarita, Sclerocytis rubiformis. A completely randomized design (CRD) consisted of 6 treatments were applied into two types of soil, was Lombok soil and Parung soil. Each treatment was repeated 3 times, so that there were 36 experimental units. Treatments given were as follow: (1) Without mycorrhiza and without P source (Control); (2) fertilizer SP-36; (3) Mycofer mycorrhiza; (4) Mycofer Mycorrhiza + SP 36 fertilizer; (5) Mikorbi mycorrhiza from Lombok; (6) Mikorbi mycorrhiza from Lombok + SP 36 fertilizer. The results showed that combination mikorbi mycorrhiza and fertilizer SP 36 on Parung soil can increase stover production by 57.35% compared to control, by 9.73% compared to the mycofer mycorrhiza and fertilizer SP 36. The results showed that mycorrhiza is suitable to use in soils with low P content, so that they could help increase the availability of P in the soil and be easily absorbed by plants.