Maize Growth Responses to a Humic Product in Iowa Production Fields: An Extensive Approach

Field evaluations of commercial humic products have seldom involved replication across location or year. To evaluate the consistency of humic product efficacy in field conditions, we determined the effects of a humic product on maize (Zea mays L.) growth in high-yielding Midwestern (US) fields through the following two extensive approaches: (i) replicated strip plots in five site—year combinations from 2010 to 2013; and (ii) demonstration strips in 30–35 production fields annually from 2009 to 2011 that covered major areas of Iowa. Mechanized combine measurements of grain yield showed increases of 0.2–0.4 Mg ha–1 (1–4%) with humic product application for all five site—year combinations of the replicated strip plots. Six of 10 humic treatments within the fields responded positively (P < 0.07), and the positive responses of two more treatments approached significance at the benchmark of P = 0.10. In the demonstration strips, maize grain weight in hand-collected samples increased significantly (P < 0.004) with humic product application in each of the three growing seasons, and across all the three seasons by 6.5% (P < 0.001). Grain weight increased numerically for 76 of the 98 demonstration strips. Yield component analysis for both the replicated strip plots and the demonstration strips attributed the yield boosts largely to increased ear length, especially of the shorter ears. Humic product application caused significantly (P < 0.10) greater total leaf area in all eight field treatments at three site—year combinations. Humic product application did not consistently affect nutrient concentrations of the grain or stover or any measured soil property. These results represent among the widest geographic evaluations published on field efficacy of a humic product. They demonstrate the capability of a humic product to improve maize growth in high-yielding conditions.

Growth and yields of two varieties of maize (Zea mays L.) intercropped with peanut (Arachys hypogaea L.) applied by bokashi plus fertilizer between the rows of teak trees based agroforestry system

Nutrient shortages are the main problems faced by farmers, so as to improve soil fertility using organic fertilizer is compulsory. The main objective was to analyze the effects of bokashi plus fertilizer on the growth and yields of two varieties of maize intercropped with peanut under three years old teak trees in agroforestry system. The research was arranged in randomized completely block design in factorial pattern with two factors, maize variety: local maize and hybrid corn bisi-2; and bokashi plus fertilizer doses: 0, 3, 6 and 9 t ha-1. Maize growth recorded were plant height, leaf number, stem diameter and leaf area at 2, 4, 6 and 8 WAP and maize yields recorded were cob weight with cornhusk, cob weight without cornhusk, cob length, diameter, row number, 100 seeds dry weight, biomass dry weight, yield and LER. The results showed that interaction between maize variety and bokashi plus fertilizer had significant effect on the growth and yield of maize intercropped with peanut under three years of teak trees in agroforestry system. The best effects of maize growth and yield were obtained at 9 t ha-1 with highest yield of local maize and hybrid maize of 4,69 and 5,79 t ha-1.

Utilization of Tithonia diversifolia and sugarcane leaves to improve soil properties and plant growth on a sandy soil of Malang, East Java

A study on the addition of organic matter of different qualities was carried out to improve plant growth on a degraded sandy soil of Bambang Village, Wajak Malang, East Java. Two potential sources of organic matter in Bambang Village are Tithonia diversifolia and sugarcane leaves. This study aimed at elucidating the changes in some chemical properties of a degraded sandy soil of Malang, East Java, and nutrient uptake and growth of maize plants by applying mixtures of Tithonia diversifolia and sugarcane leaves of different quality. Treatments tested in this study were mixtures of Tithonia diversifolia leaves and sugarcane leaves at various proportions (%w/w), i.e. 100% Tithonia diversifolia leaves (T1), 100% sugarcane leaves (T2), 75% Tithonia diversifolia leaves + 25% sugarcane leaves (T3), 50% Tithonia diversifolia leaves + 50% sugarcane leaves (T4); without organic matters (T6), and control, without organic matter and inorganic fertilizers (T7). The results showed that the application of Tithonia diversifolia and sugarcane leaves affected soil pH, soil exchangeable bases, maize growth, and nutrients uptake. Nutrients taken up by maize plants significantly increased with the addition of Tithonia diversifolia leaves, either alone or in combination with sugarcane leaves. The application of 100% sugarcane leaves did not significantly affect maize growth and nutrient uptake.

Reintroduction of Decomposed Straw To Maize Fields Resulted In Soil Microbial Community Change And Increased Corn Production

Purpose Returning decomposed straw to crop fields could address many agricultural shortcomings. In this study, the soil microbial community, soil nutrients, soil enzyme activities and maize yield were investigated after returning decomposed straw to the field. Methods To investigate the effects of returning decomposed straw to field on soil microorganisms and maize growth, field experiments were carried out to measure soil nutrient content, soil enzyme activity and maize yield, and the soil microbial community structure was measured by 16SRNA and ITS amplicon sequencing technology.Results The results showed that the contents of total nitrogen (TN), nitrate nitrogen (NN), total phosphorus (TP), available phosphorus (AP) and pH were significantly increased, and the contents of ammonium nitrogen (AN) and available kalium were decreased in both the rotary tillage (SR) and mulching (SM) treatments. The bacterial and fungal community structures in bulk and rhizosphere soils were clearly changed under SR and SM. The relative abundances of bacterial genera related to soil denitrification, such as Skermanella, Blastococcus, Geodermatophilus and Asanoa, were significantly increased. The relative abundances of Conexibacter, Streptomyces and Trichoderma, which bacteria that has shown to inhibit plant diseases, were increased. In addition, the relative abundances of growth-promoting bacteria, such as Arthrobacter and Mesorhizobium, were also significantly increased. Moreover, adding decomposed straw back to the field promoted the absorption of nutrients by maize, and resulted in higher yield of maize.Conclusions Our findings suggest positive responses of soil microbial community structure and maize growth to decomposition straw returning.