Cattle manure and inorganic nitrogen fertilizer application effects on soil hydraulic properties and maize yield of two soils of Murewa district, Zimbabwe

Abstract

This study set out to determine the effects of cattle manure and inorganic N-fertilizer application on the hydraulic properties and maize yield of a clay and sandy soil in a smallholder farming area of Zimbabwe. Four fields classified as homefields (HF: more fertile and closer to homesteads) and outfields (OF: less fertile and further from the homesteads) were selected on clay and sandy soil. They were subjected to four treatments, control (no fertility amendment), 5, 15 and 25 t/ha cattle manure + 100 kg/ha N (as ammonium nitrate) for 7 years. A two-way randomized complete block design was used with fertility and field type as the two factors. Clay soil hydraulic properties, which included density of macropores with a diameter >300 lm, unsaturated hydraulic conductivity, steadystate infiltration rate, moisture retention under low suction and maize grain yield, were significantly improved (P < 0.05) by fertility management compared with the control and were generally comparable between the HF and OF. Fertility management significantly improved maize grain yield on sandy soils but did not enhance hydraulic parameters, thereby indicating poor responsiveness in structural build-up. On the other hand, significantly different hydraulic parameters between the sandy soil HF and OF suggested effects of other factors not related to soil fertility and field type treatments. We therefore concluded that application of a high rate (25 t/ha) of cattle manure and inorganic Nfertilizer is beneficial for fertility restoration to the degraded OFs with associated comparable hydraulic properties on HFs and OFs on clay soil, unlike on sandy soil.

Soil hydrological properties as influenced by long‐term nitrogen application and landscape positions under switchgrass seeded to a marginal cropland

“…A significantly positive correlation of q s with HWC and SOC (Table ) also supports these results. In an experiment conducted by Dunjana, Nyamugafata, Nyamangara, and Mango (), a significant increase in q s was observed due to 100 kg N/ha on clayey soil as compared to the control. The q s significantly increased with the increase in N rate under a long‐term experiment in Oregon, USA (Zuzel et al, ).…”

Maize Water Productivity and Its Relationship to Soil Properties under Integrated Cattle Manure and Mineral‐Nitrogen Fertilizer in a Smallholder Cropping System

“…The experiment consisted of four fields selected to represent two soil fertility domains: the characteristically more fertile HFs and the less fertile OFs on the two soil types (Zingore et al, 2007). A detailed description of the experimental set up is presented in two earlier studies (Dunjana et al, 2012, 2014). Note that testing the effects of soil type and field type as experimental factors was beyond the scope of the current study.…”

“…Composite samples were collected from all treatments in all fields, air‐dried and analyzed using the following methods: soil organic C (SOC) was measured via the modified Walkley–Black method (Houba et al, 1989); macroaggregate stability was measured as the macroaggregate index (Ima) via a wet sieving method (Kemper and Rosenau, 1986); aggregate‐protected C was determined using an aggregate incubation assay (Beare et al, 1994; steady‐state infiltration rate (SSIR) was measured using double‐ring infiltrometry (Anderson and Ingram, 1993); pore density was measured via double‐ring infiltrometry in conjunction with a tension infiltrometer (Watson and Luxmoore, 1986); and unsaturated hydraulic conductivity was measured using a tension infiltrometer (Commonwealth Scientific and Industrial Research Organisation, 1988). Full details of the methods used in the determination of soil physical and hydraulic characteristics are given in earlier works (Dunjana et al, 2012, 2014).…”

“…Principal component analysis (PCA) was used to determine the relationship between MWP and soil properties that significantly responded to cattle manure and mineral‐N fertilizer application. These included SOC, Ima, aggregate‐protected C, SSIR, macropore density >300 μm in diameter (MD 300 ), and unsaturated hydraulic conductivity (Dunjana et al, 2012, 2014). Principal component analysis avoids multicollinearity by grouping properties that are strongly correlated into independent linear combinations (factors) used in subsequent regression analysis.…”

“…Maize water productivity was determined from clay and sandy fields that previously exhibited variable fertility typically classified as homefield (HF: more fertile and closer to homesteads) and outfield (OF: less fertile and further from homesteads). However, 7 yr of balanced fertilizer application significantly and comparably improved soil physical fertility to both HFs and OFs on clay soil (Dunjana et al, 2012, 2014). Furthermore, we sought to determine the relationship between MWP and selected soil physical properties under combined cattle manure and mineral‐N fertilizer application.…”